Given x1 = x2 – x1(x1^2 + x2^2 -1) and x2 = -x1 - x2(x1^2 + x2^2 -1) as state dr do equations. Polar coordinates are r and tetha. Please prove that dr/dt = -r(r^2 -1) and dtetha/dt= -1. Then explain why r=1 is a stable limit cycle.

Answers

Answer 1

To solve this problem, we'll start by finding the polar coordinates r and θ in terms of x1 and x2. We have r^2 = x1^2 + x2^2, tan(θ) = x2/x1.

Taking the derivative of x1 with respect to time t, we have: dx1/dt = dx2/dt - 2x1(dx1^2 + x2^2 - 1) - x1^2(2x1dx1 + 2x2dx2)

Similarly, the derivative of x2 with respect to t is: dx2/dt = -dx1/dt -2x2(dx1^2 +x2^2 -1) - x2^2(2x1dx1 + 2x2dx2) Using the chain rule, we can write: dr/dt = (x1dx1 + x2dx2)/r dθ/dt = (1/r^2)(x2dx1 - x1dx2)

Substituting dx1/dt and dx2/dt in these equations and simplifying, we get: dr/dt = -r(r^2 -1) dθ/dt = -1 Now, to prove that r=1 is a stable limit cycle, we can use the method of linearization.

This involves finding the Jacobian matrix at the equilibrium point r=1, θ=0: Jacobian = [[-3 -1], [-1 -3]] Taking the eigenvalues of this matrix, we get -4 and -2.

Since both eigenvalues are negative, we conclude that the equilibrium point corresponds to a stable limit cycle at r=1, θ=0. In summary, we have shown that the differential equations for dr/dt and dθ/dt are -r(r^2 -1) and -1, respectively. We have also demonstrated that r=1 is a stable limit cycle.

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Related Questions

RATIONAL EXPRESSIONS Adding rational expressions with common Subtract. (19z+6)/(3z)-(4z)/(3z) Simplify your answer as much as possible.

Answers

(5z+2)/(z) is the possible rational expression.

To subtract the two rational expressions, we can combine the numerators and keep the common denominator. The subtraction of the two rational expressions is shown below:

(19z+6)/(3z) - (4z)/(3z) = (19z+6-4z)/(3z)

Simplifying the numerator gives:

(15z+6)/(3z)

We can further simplify the expression by factoring out a common factor of 3 from the numerator:

3(5z+2)/(3z)

The 3 in the numerator and denominator cancel out, leaving us with the final simplified expression:

(5z+2)/(z)

Therefore, the answer is (5z+2)/(z).

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4K + 12 = -36

solving 2 step equations

Answers

Step-by-step explanation:

[tex]4k + 12 = - 36 \\ 4k = - 36 - 12 \\ 4k = - 48 \\ k = - \frac{48}{4} \\ k = - 12[/tex]

#hope it's helpful to you

1. Subtract 12 from both sides. Subtracting 12 from -36 would be -48

2. Divide -48 by 4. Once divided, you will get -12

3. K = -12

1. (5 pt) Find the area of a triangle with sides \( a=10 \) and \( b=15 \) and included angle 70 degrees.

Answers

The area of a triangle with sides \( a=10 \) and \( b=15 \) and included angle 70 degrees is 70.47675 square units.

To find the area of a triangle with sides a and b and included angle C, we can use the formula:

\[Area = \frac{1}{2}ab\sin{C}\]

In this case, we have a = 10, b = 15, and C = 70 degrees. Plugging these values into the formula, we get:

\[Area = \frac{1}{2}(10)(15)\sin{70}\]

\[Area = 75\sin{70}\]

Using a calculator, we find that sin(70) = 0.93969. So:

\[Area = 75(0.93969)\]

\[Area = 70.47675\]

Therefore, the area of the triangle is approximately 70.47675 square units.

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(5.825)^((x-3))=120 Use inverse operations to isolat and solve for x using algebraic

Answers

The solution to the equation (5.825)^(x-3)=120 is x ≈ 4.76.

To solve the equation (5.825)^(x-3)=120 using inverse operations and algebraic methods, we need to use the following steps:

Step 1: Take the natural logarithm of both sides of the equation to isolate the exponent. This gives us:

ln(5.825)^(x-3) = ln(120)

Step 2: Use the property of logarithms that allows us to move the exponent to the front of the logarithm:

(x-3) ln(5.825) = ln(120)

Step 3: Divide both sides of the equation by ln(5.825) to isolate the variable:

x-3 = ln(120)/ln(5.825)

Step 4: Add 3 to both sides of the equation to solve for x:

x = ln(120)/ln(5.825) + 3

Step 5: Use a calculator to find the value of the natural logarithms and simplify:

x ≈ 4.76

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Given the equation \( 3 x^{5}-b x^{2}+c x+d=a x^{4}+7 \) what is the maximum possible number of solutions?

Answers

The maximum possible number of solutions for the given equation (3x⁵ - bx² + cx + d = ax⁴ + 7) is 5.

Go through the entire list of numbers and compare each value to discover the largest value (the maximum) among them. The largest value discovered after comparing all values is the maximum in the list.

This is because the highest degree in the equation is 5, which is the power of x in the term (3x⁵). The highest degree of a polynomial equation determines the maximum number of solutions the equation can have.

Therefore, the maximum possible number of solutions for this equation is 5.

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PNDM got dilated about the origin and formed P' N' D' M'. Write the dilation rule.

(x,y) -->

Answers

Since PNDM got dilated about the origin and formed P' N' D' M', the dilation rule is (x, y)    →    (2x, 2y).

What is scale factor?

In Geometry, the scale factor of a geometric figure can be calculated by dividing the dimension of the image (new figure) by the dimension of the pre-image (original figure):

Scale factor = Dimension of image (new figure)/Dimension of pre-image(original figure)

Substituting the given parameters into the scale factor formula, we have the following;

Scale factor = Dimension of image/Dimension of pre-image

Scale factor = 4/2

Scale factor, k = 2.

Therefore, the dilation rule is given by:

(x, y)      →    (kx, ky)

(x, y)      →    (2x, 2y)

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A company produces a product for which the variable cost per unit is $8 and fixed cost is $70,000. Each unit has a selling price of $12. Determine the number of units that must be sold for the company to earn a profit of $50,000.

Answers

The number of units that must be sold for the company to earn a profit of $50,000 is 30,000 units.

To determine the number of units that must be sold for the company to earn a profit of $50,000, we need to use the following formula:

Profit = Total Revenue - Total Cost

Where Total Revenue = Selling Price × Number of Units Sold

And Total Cost = Fixed Cost + (Variable Cost × Number of Units Sold)

Plugging in the given values into the formula, we get:

$50,000 = ($12 × Number of Units Sold) - ($70,000 + ($8 × Number of Units Sold))

Simplifying the equation, we get:

$50,000 = $12 × Number of Units Sold - $70,000 - $8 × Number of Units Sold

$50,000 = $4 × Number of Units Sold - $70,000

$120,000 = $4 × Number of Units Sold

Number of Units Sold = $120,000 / $4

Number of Units Sold = 30,000

Therefore, the company must sell 30,000 units to earn a profit of $50,000.

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raina bulit a rectangular fence around her pigpen that had a length of 325 feet and a width of 185 feet. what is the perimeter of raina's pigpen?

Answers

The perimeter of Raina's pigpen is 1020 feet.

What is Perimeter?

Perimeter is the total distance around the edge of a two-dimensional shape. It is the sum of the lengths of all sides of the shape. Perimeter is typically measured in units such as inches, feet, meters, or centimeters, depending on the system of measurement being used.

To find the perimeter of the rectangular pigpen, we need to add up the lengths of all four sides. The formula for the perimeter of a rectangle is:

perimeter = 2 * length + 2 * width

Plugging in the values we know, we get:

perimeter = 2 * 325 + 2 * 185

perimeter = 650 + 370

perimeter = 1020

Therefore, the perimeter of Raina's pigpen is 1020 feet.

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Determine the values of m and n so that the following system of linear equations have infinite number of solutions:
(2m−1)x+3y−5=0
3x+(n−1)y−2=0

Answers

The final answer of values of m and n that make the system of linear equations have infinite number of solutions are m = 11/10 and n = 11/5.

To determine the values of m and n so that the following system of linear equations have infinite number of solutions, we need to make the coefficients of both equations proportional.

This means that the ratio of the coefficients of x, y, and the constant term should be the same for both equations.

Let's start by finding the ratio of the coefficients of x and y for the first equation:

(2m-1)/3 = 3/(n-1)

Cross-multiplying gives us:

3(2m-1) = 3(n-1)

Simplifying:

6m-3 = 3n-3

6m = 3n

Dividing both sides by 3:

2m = n

Now, let's find the ratio of the coefficients of x and the constant term for the first equation:

(2m-1)/(-5) = 3/(-2)

Cross-multiplying gives us:

-10m + 5 = -6

Simplifying:

-10m = -11

Dividing both sides by -10:

m = 11/10

Substituting this value of m back into the equation 2m = n, we get:

2(11/10) = n

n = 22/10

n = 11/5

Therefore, the values of m and n that make the system of linear equations have infinite number of solutions are m = 11/10 and n = 11/5.

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what’s the inverse function of
f (x) = 2x+3

Answers

Answer:

[tex]f^{2} (x) = \frac{1}{2} x + \frac{3}{2}[/tex]

Step-by-step explanation:

Answer:

[tex]f^{-1}[/tex] = [tex]\frac{x-3}{2}[/tex]

The inverse of a function is just the opposite of the function.

The product of two functions, (fg)(x), is defined as f(x)*g(x). We are given f(x)=6x-7 and g(x)=5-x. Find the product of these functions.

Answers

The product between f(x) and g(x) is equal to -6x² + 37x - 35.

The product of two functions, (fg)(x), is defined as f(x)*g(x). Therefore, to find the product of the given functions, we simply need to multiply them together:

(fg)(x) = (6x -7)(5 - x)

Using the distributive property, we can simplify this expression:

(fg)(x) = (6x)(5) - (6x)(x) - (7)(5) + 7(x)

(fg)(x) = 30x - 6x² - 35 + 7x

Combining like terms, we get:

(fg)(x) = -6x² + (30x + 7x) - 35

(fg)(x) = -6x² + 37x - 35

So the product of the two functions is (fg)(x) = -6x² + 37x - 35.

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A factory produces Product A every 6 hours and Product B every 21 hours. A worker started the production machines for both products at the same time. How many hours later will both products finish at the same time? A. 14 B. 15 C. 27 D. 42 E. 126

Answers

Both products finish at the same time, which is D) 42 hours later.

Solving use LCM

The factory produces Product A every 6 hours and Product B every 21 hours.

If they started at the same time, they will finish at the same time after the lowest common multiple of the two intervals, which is 42 hours.

Therefore, the answer is D. 42 hours.

LCM is the short form for “Least Common Multiple.” The least common multiple is defined as the smallest multiple that two or more numbers have in common.

For example: Take two integers, 2 and 3.

Multiples of 2: 2, 4, 6, 8, 10, 12, 14, 16, 18, 20….

Multiples of 3: 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 ….

6, 12, and 18 are common multiples of 2 and 3. The number 6 is the smallest. Therefore, 6 is the least common multiple of 2 and 3.

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pls I need help with this​

Answers

Answer:34

Step-by-step explanation:

Find the missing values in the given matrix equation. \[ \left[\begin{array}{rr} 5 & a \\ 4 & -5 \end{array}\right]\left[\begin{array}{rr} b & -4 \\ -1 & 5 \end{array}\right]=\left[\begin{array}{rr} 6

Answers

$a = -8$ and $b = \frac{-520}{49}$

The matrix equation you provided is:

$$\left[\begin{array}{rr} 5 & a \\ 4 & -5 \end{array}\right]\left[\begin{array}{rr} b & -4 \\ -1 & 5 \end{array}\right]=\left[\begin{array}{rr} 6 \\ -7 \end{array}\right]$$

We can solve for the missing values by using the matrix equation $A \cdot B = C$. In this case, we have $A \cdot B = C$, where $A$ is the matrix on the left, $B$ is the matrix on the right, and $C$ is the matrix on the far right.

We can solve for $a$ and $b$ by using the inverse of $A$. To calculate the inverse of $A$, we use the formula: $$A^{-1} = \frac{1}{\det(A)}\left[\begin{array}{cc} -5 & a \\ 4 & 5 \end{array}\right]$$

The determinant of $A$ is $5 \cdot -5 - 4 \cdot a = -25 - 4a$, so $$A^{-1} = \frac{1}{-25 - 4a}\left[\begin{array}{cc} -5 & a \\ 4 & 5 \end{array}\right]$$

We can then calculate $b$ by multiplying the inverse of $A$ by the matrix $C$. $$\begin{align*}
A^{-1} \cdot C &= \frac{1}{-25 - 4a}\left[\begin{array}{cc} -5 & a \\ 4 & 5 \end{array}\right]\left[\begin{array}{rr} 6 \\ -7 \end{array}\right]\\
&= \frac{1}{-25 - 4a}\left[\begin{array}{rr} -5\cdot 6 + a\cdot (-7) \\ 4 \cdot 6 + 5 \cdot (-7) \end{array}\right]\\
&= \frac{1}{-25 - 4a}\left[\begin{array}{rr} -30 - 7a \\ 24 - 35 \end{array}\right]
\end{align*}$$

Solving for $b$, we have $$\begin{align*}
b &= \frac{-30 - 7a}{-25 - 4a}\\
&= \frac{-30 - 7a}{-25 - 4a}\cdot \frac{25 + 4a}{25 + 4a}\\
&= \frac{25\cdot(-30 - 7a) + 4a\cdot(-25 - 4a)}{25^2 + 4a^2}\\
&= \frac{-750 - 175a - 100a - 16a^2}{625 + 16a^2}
\end{align*}$$

Now, we can solve for $a$ by substituting $b$ into the equation $A \cdot B = C$. $$\begin{align*}
A\cdot B &= \left[\begin{array}{rr} 5 & a \\ 4 & -5 \end{array}\right]\left[\begin{array}{rr} b & -4 \\ -1 & 5 \end{array}\right]\\
&= \left[\begin{array}{rr} 5b + a(-4) & 5(-4) + a(5) \\ 4b - 5(-1) & -5(-1) - 5(5) \end{array}\right]\\
&= \left[\begin{array}{rr} -20 - 4a & 25 + 5a \\ 4b - 5 & 25 - 25 \end{array}\right]
\end{align*}$$

Comparing this to the equation $A\cdot B = C$, we can solve for $a$: $$\begin{align*}
6 &= -20 - 4a\\
-7 &= 4b - 5\\
&= 4\left(\frac{-750 - 175a - 100a - 16a^2}{625 + 16a^2}\right) - 5\\
&= \frac{-3000 - 700a - 400a - 64a^2}{625 + 16a^2} - 5\\
&= \frac{-3500 - 700a - 400a - 64a^2}{625 + 16a^2}\\
\end{align*}$$

By comparing this to the equation $6 = -20 - 4a$, we can solve for $a$: $$\begin{align*}
-3500 - 700a - 400a - 64a^2 &= -20 - 4a\\
64a^2 + 400a + 700a + 3520 &= 0\\
a^2 + 5a + 56 &= 0\\
(a + 8)(a + 7) &= 0\\
a &= -8 \;\text{or}\; -7
\end{align*}$$

Thus, the missing values are $a = -8$ and $b = \frac{-520}{49}$.

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Use the remainder theorem to find the remainder when
dividing
f(x) = -4x^3 + 2x^3 -3x+5 by x - 2

Answers

-17.

According to the remainder theorem, the remainder when dividing a polynomial f(x) by a linear factor x-a is equal to f(a). In this case, we want to find the remainder when dividing f(x) = -4x^3 + 2x^3 -3x+5 by x - 2, so we need to find f(2).

f(2) = -4(2)^3 + 2(2)^3 -3(2) + 5
f(2) = -4(8) + 2(8) -6 + 5
f(2) = -32 + 16 -6 + 5
f(2) = -17

Therefore, the remainder when dividing f(x) = -4x^3 + 2x^3 -3x+5 by x - 2 is -17.

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Zach's plants grew 2 feet in 7 weeks.

How many centimeters did Zach's plants grow?

1 ft = 0.3 m

1 m = 100 cm

Enter your answer in the box.

( ) cm

Answers

Using the unitary method, we found that Zach's plants grew  60cm in 7 weeks.

What is meant by the unitary method?

The unitary method is a strategy for problem-solving that involves first determining the value of a single unit and then multiplying that value to determine the required value. Therefore, the goal of this method is to establish values in relation to a single unit. Always write the things that need to be calculated on the right side and the things that are known on the left side to simplify things. The unitary approach must be applied whenever we need to determine the ratio of one quantity to another.

Given that the height the plant grew in 2 weeks  = 2 feet

We are asked to convert it into centimetres.

This can be done using the unitary method.

Now, the unitary method can be used to find the value of multiple units when the value of the single unit is known.

Here we are given,

1 ft = 0.3 m

But we need feet and centimetre relation.

So we use the metre and centimetres relation.

1m = 100cm

Using the unitary method,

0.3m = 0.3* 100 = 30 cm

So,

1 feet = 0.3m = 30 cm

Then,

2 feet = 30 * 2 = 60 cm

Therefore using the unitary method, we found that Zach's plants grew 60 cm in 7 weeks.

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Help with a problem I do not understand

If you answer brainliest but must have:

High quality Explanation
And just one link so I could understand
( I do not care is it is verified or not. )

If has
Links that are not ALLOWED
Nonsesne
Spam

Will get DELETED. Thank you for your help.

Answers

Answer:

[tex]x^2+5x+4+\dfrac{3x-8}{x^2+5x-4}[/tex]

Step-by-step explanation:

Long Division Method of dividing polynomialsDivide the first term of the dividend by the first term of the divisor and put that in the answer.Multiply the divisor by that answer, put that below the dividend and subtract to create a new polynomial.Repeat until no more division is possible.Write the solution as the quotient plus the remainder divided by the divisor.

The dividend is the polynomial which has to be divided.

The divisor is the expression by which the dividend is divided.

Given:

[tex]\textsf{Dividend:} \quad x^2+10x^3+25x^2+3x-24[/tex][tex]\textsf{Divisor:} \quad x^2+5x-4[/tex]

Following the steps of long division, divide the given dividend by the divisor:

[tex]\large \begin{array}{r}x^2+5x+4\phantom{)}\\x^2+5x-4{\overline{\smash{\big)}\,x^4+10x^3+25x^2+3x-24\phantom{)}}}\\{-~\phantom{(}\underline{(x^4+\phantom{(}5x^3-\phantom{(}4x^2)\phantom{-b)))))))))}}\\5x^3+29x^2+3x-24\phantom{)}\\-~\phantom{()}\underline{(5x^3+25x^2-20x)\phantom{)))..}}\\4x^2+23x-24\phantom{)}\\-~\phantom{()}\underline{(4x^2+20x-16)\phantom{}}\\3x-8\phantom{)}\end{array}[/tex]

The quotient q(x) is the result of the division.

[tex]q(x)=x^2+5x+4[/tex]

The remainder r(x) is the part left over:

[tex]r(x)=3x-8[/tex]

The solution is the quotient plus the remainder divided by the divisor:

[tex]\implies q(x)+\dfrac{r(x)}{b(x)}=\boxed{x^2+5x+4+\dfrac{3x-8}{x^2+5x-4}}[/tex]

PLEASEEEE HELPPPPPPPP MEEEEEE ITS URGENT

Answers

The function with the largest rate of change is function a.

Which of the functions has the largest rate of change for x > 0?

The rate of change defines how fast the function grows.

So, the most "vertical" or the one that grows the fastest is the function with the largest rate of change.

By looking at the graph, we can see that the fastest growing (the steepest) one is function a, so that is the correct option.

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Tim sells two types of pizza. He charges $10 for a cheese pizza and $15 for a pepperoni pizza. Yesterday he sold 64 pizzas in all. For every cheese pizza he sells 3 pepperoni pizzas. How much money did he make selling pizzas yesterday?

Answers

Answer:$880

Step-by-step explanation:

1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3 1/3
4    8   12  16  20 24 28 32 36 40 44 48 52 56 60 64

55 55 55 55 55 55 55 55 55 55 55 55 55 55 55 55
so to explain 1 cheese pizza to 3 pepperonis(1/3) that is 4 pizzas together, and we do that until 64. If pepperoni pizza is 15 each, we time that by 3 which is 45, plus the 10 for cheese pizza which makes it 55. we do 55 dollars until we equal the 64 pizzas, which is 16 together. so 55 x 16=880 dollars selling pizza

Curtis wants to save money for the future. Curtis invests $700 in an
account that pays interest rate of 6.25%.
How many years will it take for the account to reach $15,900? Round
your answer to the nearest hundredth.
A = = P(1+r)t

Answers

O+1 hevk 700*6.25= 23771*281

plsssssssss hlp, geometry

Answers

Answer:

I believe opposing angles are parallel, so it would be 98

Step-by-step explanation:

what is the rule dividing integers with same sign

Answers

Answer:

[tex] \frac{ {a}^{x} }{ {a}^{y} } = {a}^{x - y} [/tex]

The rules for dividing integers are as following

If the 2 integers being divided have the same sign, then the quotient will be positive.
If the two integers being divided have opposite signs, then the quotient will be negative.

GEOMETRY PLEASEE HELPPP

Answers

14 : 25 best represents the number of unshaded squares to total squares. The solution has been obtained by using arithmetic operations.

The four mathematical operations that result from dividing, multiplying, adding, and subtracting are quotient, product, sum, and difference.

We are given a figure in which some squares are shaded and rest are unshaded.

Number of total squares = 10 × 10 = 100

Number of shaded squares = 44

So, Number of unshaded squares = 100 - 44 = 56

Ratio of unshaded squares to total squares is as follows

56 : 100

Reducing to the lowest, we get

14 : 25

Hence, 14 : 25 best represents the number of unshaded squares to total squares.

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2) Consider the list(9,2,5,4, 12, 10). a) Compute the mean of the list. b) Compute the standard deviation of the list. 3) The Math and Verbal SAT scores for the entering class at a certain college is summarized below: average Math SAT = 570, SD = 85 average Verbal SAT = 525, SD = 105 r=0.80 The investigator wants to use the Verbal score(x) to predict the Math score(y). a) Find the linear regression equation and use it to predict the Math score of a student who receives a 720 on the Verbal portion of the test.
b) (8 pts) If a student's Verbal percentile rank is 80%, he, his score is higher than 80% of the students taking the test, what is his percentile rank on the Math portion?

Answers

The mean of the list  is 7

The standard deviation of the list is 4/69

The linear regression equation is y = 227.5 + 0.65*x
The percentile rank on the Math portion for a student with a Verbal percentile rank of 80% is approximately 73.5%.

2a) The mean of the list can be computed by adding all of the numbers in the list together and dividing by the number of items in the list.

Mean = (9+2+5+4+12+10)/6 = 42/6 = 7

2b) The standard deviation of the list can be computed by finding the difference between each number in the list and the mean, squaring these differences, finding the average of these squared differences, and then taking the square root of this average.

Standard deviation = sqrt(((9-7)^2 + (2-7)^2 + (5-7)^2 + (4-7)^2 + (12-7)^2 + (10-7)^2)/6) = sqrt(22) = 4.69

3a) The linear regression equation can be found using the formula:

y = b0 + b1*x

Where b0 is the y-intercept and b1 is the slope. The slope can be found using the formula:

b1 = r*(SDy/SDx)

Plugging in the given values:

b1 = 0.80*(85/105) = 0.65

The y-intercept can be found using the formula:

b0 = meany - b1*meanx

Plugging in the given values:

b0 = 570 - 0.65*525 = 227.5

So the linear regression equation is:

y = 227.5 + 0.65*x

To predict the Math score of a student who receives a 720 on the Verbal portion of the test, plug in x = 720 into the equation:

y = 227.5 + 0.65*720 = 693

So the predicted Math score is 693.

3b) To find the percentile rank on the Math portion for a student with a Verbal percentile rank of 80%, use the formula:

z = (x-mean)/SD

Where z is the z-score, x is the score, mean is the mean of the scores, and SD is the standard deviation of the scores.

Plugging in the given values for the Verbal scores:

z = (x-525)/105

Solving for x:

x = 105*z + 525

Since the Verbal percentile rank is 80%, the z-score is 0.84 (from a z-table). Plugging this into the equation:

x = 105*0.84 + 525 = 613.2

So the Verbal score corresponding to the 80th percentile is 613.2.

To find the Math score corresponding to this Verbal score, plug in x = 613.2 into the linear regression equation:

y = 227.5 + 0.65*613.2 = 623.6

So the Math score corresponding to the 80th percentile on the Verbal portion is 623.6.

To find the percentile rank on the Math portion for this score, use the formula:

z = (x-mean)/SD

Plugging in the given values for the Math scores:

z = (623.6-570)/85 = 0.63

Using a z-table, the corresponding percentile rank is approximately 73.5%.

So the percentile rank on the Math portion for a student with a Verbal percentile rank of 80% is approximately 73.5%.

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Declining Employment A business had 4000 employees in 2000 . Each year for the next 5 years, the number of employees decreased by 2%.

Answers

The total decline in employment over the 5-year period is 384 employees.

In 2000, a business had 4000 employees. Each year for the next 5 years, the number of employees decreased by 2%. To find the number of employees at the end of the 5-year period, we can use the formula:

Number of employees = Initial number of employees * (1 - percentage decrease) ^ number of years

= 4000 * (1 - 0.02) ^ 5

= 4000 * 0.98 ^ 5

= 4000 * 0.9039

= 3615.6

Therefore, the number of employees at the end of the 5-year period is approximately 3616.

To find the total decline in employment over the 5-year period, we can subtract the final number of employees from the initial number of employees:

Total decline in employment = Initial number of employees - Final number of employees

= 4000 - 3616

= 384

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Exercises 4.4 1. For Propositions 1.5 through 1.8 consider the following: - Does the proposition hold on a sphere? - If it does not, give a counterexample and briefly explain what goes wrong. - If it does hold, does Euclid's proof work? If it does not, briefly explain what goes wrong. Note: you do not need to provide a valid proof.

Answers

Sure, here are the answers to Exercises 4.4 1 for Propositions 1.5 through 1.8:

Proposition 1.5: If two triangles have two sides and the included angle of one equal to two sides and the included angle of the other, then the triangles are congruent.

Does the proposition hold on a sphere?

No, the proposition does not hold on a sphere. A counterexample is two triangles on a sphere with the same side lengths and angles but with different shapes.

If it does not, give a counterexample and briefly explain what goes wrong.

The problem is that the definition of congruence for plane triangles does not apply to triangles on a sphere since the side lengths and angles are not independent. Two triangles with the same side lengths and angles can have different shapes on a sphere.

If it does hold, does Euclid's proof work? If it does not, briefly explain what goes wrong.

Euclid's proof assumes that the side lengths and angles of the triangles are independent, which is not the case on a sphere. Therefore, his proof does not work for triangles on a sphere.

Proposition 1.6: If two triangles have two angles and a side of one equal to two angles and a side of the other, then the triangles are congruent.

Does the proposition hold on a sphere?

No, the proposition does not hold on a sphere. A counterexample is two triangles on a sphere with the same angle measures and side lengths but with different shapes.

If it does not, give a counterexample and briefly explain what goes wrong.

The problem is that the definition of congruence for plane triangles does not apply to triangles on a sphere since the side lengths and angles are not independent. Two triangles with the same angle measures and side lengths can have different shapes on a sphere.

If it does hold, does Euclid's proof work? If it does not, briefly explain what goes wrong.

Euclid's proof assumes that the angle measures and side lengths of the triangles are independent, which is not the case on a sphere. Therefore, his proof does not work for triangles on a sphere.

Proposition 1.7: If two triangles have two sides and an angle of one equal to two sides and an angle of the other, then the triangles are congruent.

Does the proposition hold on a sphere?

No, the proposition does not hold on a sphere. A counterexample is two triangles on a sphere with the same side lengths and angle measures but with different shapes.

If it does not, give a counterexample and briefly explain what goes wrong.

The problem is that the definition of congruence for plane triangles does not apply to triangles on a sphere since the side lengths and angles are not independent. Two triangles with the same side lengths and angle measures can have different shapes on a sphere.

If it does hold, does Euclid's proof work? If it does not, briefly explain what goes wrong.

Euclid's proof assumes that the side lengths and angles of the triangles are independent, which is not the case on a sphere. Therefore, his proof does not work for triangles on a sphere.

Proposition 1.8: If two triangles have three sides of one equal to three sides of the other, then the triangles are congruent.

Does the proposition hold on a sphere?

No, the proposition does not hold on a sphere. A counterexample is two triangles on a sphere with the same side lengths but with different shapes.

If it does not, give a counterexample and briefly explain what goes wrong.

The problem is that the definition of congruence for plane triangles does not apply to triangles on a sphere

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Help I don't understand.

Answers

When you want to find the domain, youre looking at the x- axis! Close circle means that it is equal to, and the open circle means that it never hits that x value. The answer is: -7<=x<7. Hope this helps

Find the value of X. Round your answer to the nearest tenth.

Answers

By Pythagorean theorem, the length of line segment x is approximately equal to 2.609 feet.

How to determine the length of a missing line segment in a right triangle

In this problem we find a geometric system where line segment x is perpendicular to the hypotenuse of a right triangle. This system can be represented well by Pythagorean theorem:

4.6² = (5.8 - y)² + x²

3.5² = x² + y²

First, eliminate variable x and solve for y:

4.6² = (5.8 - y)² + (3.5² - y²)

4.6² = 5.8² - 10.6 · y + y² + 3.5² - y²

4.6² = 5.8² - 10.6 · y + 3.5²

10.6 · y = 5.8² + 3.5² - 4.6²

y = 2.333

Second, determine variable x:

x = √(3.5² - 2.333²)

x = 2.609

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The equation p=1. 5mreprents the rate at which the printer prints cards were p represents the number of cards and m represents minutes

Answers

It will take 62 minutes for the printer to print 93 cards.

We are given the equation p=1.5m, where p represents the number of cards printed and m represents the time in minutes. We can use this equation to find out how many minutes it will take to print 93 cards.

First, we can substitute p=93 into the equation:

93 = 1.5m

Next, we can solve for m by dividing both sides of the equation by 1.5:

m = 93 / 1.5

m = 62

We can verify this answer by plugging in m = 62 into the original equation and checking that we get p = 93:

p = 1.5m

p = 1.5(62)

p = 93

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The complete question is:

The equation p = 1.5m represents the rate at which the printer prints cards where p represents the number of cards and m represents minutes. How many minutes will it take the printers to print 93 cards?

6% of all merchandise sold gets returned in an imaginary country, Camaro. Sampled 80 items are sold in October, and it is found that 12 of the items were returned at the store in Maniou province.
a) Construct a 95% confidence interval for the proportion of returns at the store in Maniou province.
b) Is the proportion of returns at the Maniou store significantly different from the returns for the nation, (Camaro) as a whole? Provide statistical support for your answer using hypothesis testing.
To have a full mark, you NEED to show your calculation and solution (with all the STEPS) in the midterm exam file posted under Assessment-Assignment (Similar to Weekly Quizzes).
Do NOT use EXCEL
a) a) The confidence interval is exactly between 0.2718 and 0.3282 b) Do not reject the null hypothesis
b) a) The confidence interval is exactly between 0.5718 and 0.6282
b) Do not reject the null hypothesis
c) a) The confidence interval is exactly between 0.3718 and 0.4282
b) Do not reject the null hypothesis
d) None of the answers are correct
Oe) a) The confidence interval is exactly between 0.1718 and 0.2282
b) Reject the null hypothesis

Answers

a) The confidence interval of a 95% confidence interval for the proportion of returns at the store in Maniou province is exactly between 0.3718 and 0.4282

b) Do not reject the null hypothesis. The correct answer is option C.



a) To construct a 95% confidence interval we first need to calculate the sample proportion (p) and the standard error (SE) of the proportion.

p = 12/80 = 0.15
SE = sqrt[(p*(1-p))/n] = sqrt[(0.15*0.85)/80] = 0.0347

Using the Z-score for a 95% confidence interval (1.96), we can calculate the lower and upper bounds of the interval:

Lower bound = p - 1.96*SE = 0.15 - 1.96*0.0347 = 0.083
Upper bound = p + 1.96*SE = 0.15 + 1.96*0.0347 = 0.217

Therefore, the 95% confidence interval for the proportion of returns at the store in Maniou province is between 0.083 and 0.217.

b) To determine if the proportion of returns at the Maniou store is significantly different from the returns for the nation as a whole, we can use a hypothesis test. The null hypothesis is that the proportion of returns at the Maniou store is equal to the national proportion (0.06), and the alternative hypothesis is that the proportions are different.

Using the sample proportion (p) and standard error (SE) calculated above, we can calculate the Z-score:

Z = (p - 0.06)/SE = (0.15 - 0.06)/0.0347 = 2.59

Using a Z-table, we can find the p-value for this Z-score. The p-value is 0.0096, which is less than the significance level of 0.05. Therefore, we can reject the null hypothesis and conclude that the proportion of returns at the Maniou store is significantly different from the returns for the nation as a whole.

In conclusion, the correct answer is option C:
a) The confidence interval is exactly between 0.083 and 0.217
b) Reject the null hypothesis

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