On a multiple choice test with 13 questions, each question has four possible answers, one of which is correct. For students who guess at all answers, find the standard deviation for the number of correct answers.
Select one:
A. 1.875.
B. 1.53.
C. 1.47.
D. 1.5.
E. 1.561.

Answer:

n=2

Step-by-step explanation:

⁴/5n-¹/5=²/5n

first we remove the denominators by multiplying all the numbers with their lcm

Lcm of 5n and 5 is 5n thus:

(5n×⁴/5n)-(¹/5×5n)=²/5n×5n

4-n=2

4-2=n

n=2

insert 2 insted of n

⁴/5(2)-¹/5=²/5(2)

⁴/10-¹/5=²/10. simplify

²/5-¹/5=¹/5

¹/5=¹/5

so the correct value of n is 2

Answer:

The answer is B

Answer: B

Step-by-step explanation:

In mathematics, a rational number is a number that can be expressed as the quotient or fraction p/q of two integers, a numerator p and a non-zero denominator q. Since q may be equal to 1, every integer is a rational number.

All you need to do is find which of following is a whole number or integer.

Answer:

4 by 9 should be the answer

Step-by-step explanation:

N/A

Answer:

I think it is 2/9. I'm not sure.

Step-by-step explanation:

10/18 are brown eggs.

8/18 are white eggs.

4/18 are cracked.

Simplified answer is 2/9 chance.

Answer:

For this case we have a total of 10 nonfiction books and 8 fiction books, we are going to assume that the selection is without replacement so then for the first case the probability of select a fiction book is:

[tex] \frac{8}{18}[/tex]

For the second selection we have 17 books remaining and the probability of select a nonfiction book is:

[tex] \frac{10}{17}[/tex]

For the last selection we have 16 books remaining and the probability of select a fiction book would be:

[tex]\frac{7}{16}[/tex]

Sinally since the events are independent the total probability would be:

[tex] \frac{8}{18} *\frac{10}{17}*\frac{7}{16}= 0.114[/tex]

Step-by-step explanation:

For this case we have a total of 10 nonfiction books and 8 fiction books, we are going to assume that the selection is without replacement so then for the first case the probability of select a fiction book is:

[tex] \frac{8}{18}[/tex]

For the second selection we have 17 books remaining and the probability of select a nonfiction book is:

[tex] \frac{10}{17}[/tex]

For the last selection we have 16 books remaining and the probability of select a fiction book would be:

[tex]\frac{7}{16}[/tex]

Sinally since the events are independent the total probability would be:

[tex] \frac{8}{18} *\frac{10}{17}*\frac{7}{16}= 0.114[/tex]

Answer:it’s A

Step-by-step explanation:

did the test

Answer:

Option D

Step-by-step explanation:

H(x) = 3^(2x)

G(x) = reflecting H(x) across the y-axis and shifting 2 units down

=>G(x) = 3^(-2x) - 2

3^(2x) and 3^(-2x) - 2 are valid with all values of x.

=> There is no change in the domain of H(x) and G(x), in which all values of x satisfy H(x) and G(x).

3^(-2x) > 0

=> G(x) =  3^(-2x) - 2 > -2

=> Range of G(x) is from -2 to inifinity

Answer:

D.

Step-by-step explanation:

Well lets graph it first,

Look at the image below↓

So the red line is the new line which has been reflected and shifted down 2.

Meaning the domain turns into positive numbers but still remains infinite.

And the range changes

So we can cross out A and B.

Before the range was lower than 1 and now its (-2,∞)

Thus,

answer choice D is correct.

Hope this helps :)

Answer:

5/216

Step-by-step explanation:

There are 5 possibilities that Annie will roll a 6 out of 36 possible outcomes and there 6 possible outcomes of Jose rolling doubles out of 36 if you multiply these possibilities 5/36 x 6/36 you get 5/216. Sorry if wrong that's what I put for my test.

Answer: [tex]f^{-1}(1)+f(-14)=20[/tex]

[tex]f^{-1}(-2)=10[/tex]  

Step-by-step explanation:

The given table :

x: -14,-7,-12,9,10,-2

f(x):11,-12,5,1,-2,13

Since f is invertible ( given) , then [tex]f^{-1}(x)[/tex]  exists.

Now , from table [tex]f^{-1}(1)=9[/tex]  [ x= 9 corresponding to f(x) =1]

[tex]f(-14)=11[/tex]                            [ f(x) = 11 corresponding to x=-14]

then, [tex]f^{-1}(1)+f(-14)=9+11=20[/tex]

So, [tex]f^{-1}(1)+f(-14)=20[/tex]

Also, x= 10 corresponding to f(x) =-2, then

[tex]f^{-1}(-2)=10[/tex]  

Answer:

The answer is C.

Step-by-step explanation:

The formula to find equation is y - y1 = m(x - x1).

Let (x1,y1) be (6,2) and m is -5/7.

So the equation is,

y - 2 = -5/7(x - 6)

Answer:

16.4

Step-by-step explanation:

The interquartile range is the difference between the upper and lower quartiles.

Given the five figure summary, then

upper quartile = 28.8

lower quartile = 12.4

interquartile range = 28.8 - 12.4 = 16.4

The Interquartile range is 16.4.

When values are ranked from lowest to highest, the Interquartile range designates the middle 50% of those values.

Find the median (middle value) of the bottom half and upper half of the data before calculating the interquartile range (IQR). Quartile 1 (Q1) and Quartile 3 are these values (Q3).

The interquartile range represents the variation between Q3 and Q1.

The interquartile range is calculated as follows:

The upper quartile is 28.8

The lower quartile is 12.4

The interquartile range is,

= 28.8 - 12.4

= 16.4

The value of the interquartile range is 16.4.

To know more about the Interquartile range

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Answer:

Step-by-step explanation:

[tex]Opposite =f\\Hypotenuse = 9\\Adjacent = 5\\\alpha = 50\\Using \: Pythagoras \:Theorem \\Hypotenuse^2 = Opposite^2 +Adjacent^2\\9^2 = f^2+5^2\\81=f^2+25\\81-25=f^2\\56=f^2\\\sqrt{56} = \sqrt{f^2} \\f = 2\sqrt{14} \\f = 7.483\\\\f = 7.5[/tex]

Answer:

Step-by-step explanation:

To find x we use tan

tan∅ = opposite / adjacent

From the question

The adjacent is x

The opposite is 30

So we have

tan 25° = 30/x

x tan 25 = 30

Divide both sides by tan 25

x = 30/tan 25

x = 64.34

x = 64 to the nearest tenth

Hope this helps you

Answer:

The fact that shows that p+q+r=1 is at most 2/3 is well explained from what we have below.

Step-by-step explanation:

Given that:

The maximum of function P = 2pq+2pr+2rq is at most 2/3.

where ;

p+q+r=1

From  p+q+r=1

Let make r the subject ; then r = 1 - p - q

If we replace the value for r into the given function; we have:

P = 2pq+2pr+2rq

P = 2pq+2p(1 - p - q)+2(1 - p - q)q

P = 2pq + 2p - 2p² - 2pq + 2q -2pq -2q²

P = 2p - 2p² + 2q -2pq -2q²

By applying the standard method for determining critical points we obtain:

[tex]P_p[/tex] = -4p - 2q + 2 = 0

[tex]P_q[/tex] = -4q - 2p + 2 = 0

Divide all through by 2

[tex]P_p[/tex] = -2p - q + 1 = 0

[tex]P_q[/tex] = -2q - p + 1 = 0

[tex]P_p[/tex] = -2p - q  = - 1

[tex]P_q[/tex] = -2q - p  = - 1

Multiplying both sides by - ; we have:

[tex]P_p[/tex] = 2p + q  =  1   ----- (1)

[tex]P_q[/tex] = 2q + p  =  1    ------(2)

From equation (1) ; let make q the subject ; then

2p + q = 1

q = 1 - 2p

Now; let us replace the value of q = 1-2p into equation (2) , we have:

2q + p  =  1  

2(1-2p)+ p = 1

2 - 4p+p = 1

2 - 3p = 1

3p = 2-1

p = 1/3

Replacing the value of p = 1/3 into equation (1) ; we have :

2p + q  =  1  

2(1/3) + q = 1

2/3 + q = 1

q = 1 -2/3

q = 1/3

Taking the second derivative D; we have

[tex]D = P_{pp}P_{qq}-p^2_{pq}[/tex]

D = -4 × -4 - (2²)

D = 16 - 4

D = 12

This implies that the given function has a minimum or maximum at its critical point for which  12 > 0

Therefore , the value for function p = q = r  since  p, q, and r are the proportions of A, B, and O in the  population.

Hence r = 1/3

P=2pq+2pr+2rq

P = 2(1/3)(1/3) + 2(1/3)(1/3) + 2(1/3)(1/3)

P = 6/9

P = 2/3

Answer:

The correct answer is 25.2 in.

Step-by-step explanation:

It is given that number line goes from 0 to 60 which can be used to represent a ribbon of length = 60 inches.

2 inches of the ribbon are frayed so actual length = 58 inches

Please refer to the attached image for the ribbon.

A is at 0

C is at 60

B is at 2

P is the point to divide the remaining ribbon in the ratio 2:3.

Part AB of the ribbon is frayed.

BP: PC = 2:3

Let BP = 2[tex]x[/tex] and PC = 3[tex]x[/tex]

Now, BP + PC = BC = 58 = 2[tex]x[/tex] + 3[tex]x[/tex] = 5[tex]x[/tex]

So,

[tex]5x =58\\\Rightarrow x =11.6[/tex]

BP = [tex]2\times x = 2 \times 11.6 = 23.2\ inches[/tex]

Location of the Cut = 2 + 23.2 = 25.2 inches

Alternatively, we can use the formula directly:

[tex]x = \dfrac{m} {m + n } (x_2 - x_1) + x_1[/tex]

[tex]x_1 = 2\\x_2 = 60[/tex]

m: n is the ratio 2:3

[tex]x = \dfrac{2} {2 +3 } (60- 2) + 2\\\Rightarrow 0.4 (58 )+2\\\Rightarrow 23.2+2 \\\Rightarrow \bold{25.2\ inches}[/tex]

Answer:

Yes i confirm the answer above is correct. A.) 25.2

Step-by-step explanation:

I took the test duhh

Answer:

See Attachment for graph

Step-by-step explanation:

Given

Point C

Required

Plot C when dilated by 1/2

First, we have to determine the coordinates of point C

From the attached graph;

[tex]C = (0,6)[/tex]

Next, is to determine the new point when dilated;

This is calculated as thus;

[tex]New\ Point = Old\ Point * Scale\ Factor[/tex]

[tex]C' = (0,6) * \frac{1}{2}[/tex]

Expand the bracket

[tex]C' = (0 * \frac{1}{2}, 6* \frac{1}{2})[/tex]

[tex]C' = (0, \frac{6}{2})[/tex]

[tex]C' = (0, 3)[/tex]

This implies that C' will be plotted at x =0 and y = 3

(See attached for point C')

Answer:

(0,3)

Step-by-step explanation:

Answer:

D)

[tex]5 \times {10}^{ - 12} [/tex]

Step-by-step explanation:

velocity(v) = distance/time

but distance =

[tex]3 \times {10}^{ - 4} [/tex]

and velocity =

[tex]6 \times {10}^{7} [/tex]

[tex]6 \times {10}^{7} = \frac{3 \times {10}^{ - 4} }{time} [/tex]

[tex]time = \frac{3 \times {10}^{ - 4} }{6 \times {10}^{7} } [/tex]

[tex]time = 5 \times {10}^{ - 12} [/tex]

Answer:

m<R=48.2 to the nearest tenth

Step-by-step explanation:

1. sin(m<T)=2/3

m<T=arcsin(2/3)=41.81 degrees

m<R=180-90-m<T=180-90-41.81=48.19 degrees

Answer:

y+0

As y=0 represent x-axis whose slope is 0 and intersects y-axis at the origin.

Answer: it seems to be D, but the equation makes practically no sense!

The value of the factor changes for the different amounts of service years and vacation weeks.

Step-by-step explanation: The equation means that the employee is trying to figure out the value of the "v-factor" for how vacation time is earned.

If you substitute the number of service years into the left side of the "formula" and vacation weeks on the right side, then solve for "v", v(15)=5 you get v= 1/3 or 0.33

If you substitute other numbers, like v(2)=2, so v= 1 then v(30) = 8, v = 4/15 or 0.2667. You see the factor's value decreases. The company is much more generous to to employees with one or two years of service than with the older ones.

Answer:

B. The Dress Shop.

Step-by-step explanation:

To find the best deal, we want to find the cost for one dress.

Lara's Boutique: $64 for 4 dresses.

x / 1 = 64 / 4

x = 64 / 4

x = $16 per dress.

The Dress Shop: $75 for 5 dresses.

x / 1 = 75 / 5

x = 75 / 5

x = $15 per dress.

Marge's Dresses: $160 for 8 dresses.

x / 1 = 160 / 8

x = 160 / 8

x = $20 per dress.

The boutique with the best deal will have the cheapest dresses. So, the best deal would be at B. The Dress Shop.

Hope this helps!

Answer:

A. Pr(8)   = 1/10

B.  Pr(odd)  = 1/2

C.  Pr(even)  = 1/2

D. Pr(less than 6)  = 1/2

E.  Pr(prime) = 2/5

F. Pr(3 or 8)  = 1 / 5

G. Pr(8, 9 or 10) = 3/10

H. Pr(greater than 9)  = P(10) = 1/10

Step-by-step explanation:

We assume a FAIR 10-faced die, meaning there is an equal probability of throwing any one of the ten numbers.

With 10 possible outcomes each with equal probability, the probability of throwing any number is 1/10.

(It is preferable to work with fractions in probability because fractions are exact numbers, while decimals can often be rounded, or truncated).

A. Pr(8)   means probability of throwing an 8,  therefore Pr(8) = 1/10

B. Pr(odd)  there are 5 odd number from 1 to 10, so Pr(odd) = 5/10 = 1/2

C. Pr(even)  there are 5 even number from 1 to 10, so Pr(even) = 5/10 = 1/2

D. Pr(less than 6)  there are 5 numbers less than 6 (between1 to 10),

       so Pr(less than 6) = 5/10 = 1/2

E. Pr(prime) (remember that 1 is not prime)

   A prime number is an integer not divisible by any number except one and itself.

   Between 1 to 10, the four prime numbers are 2,3,5,7

   therefore Pr(prime) = 4/10 = 2/5

F. Pr(3 or 8)  

(3 or 8) make 2 successful outcomes out of 10, so Pr(3 or 8) = 2/10 = 1 / 5

G. Pr(8, 9 or 10)

similarly, (8,9 or 10) make three successful possible outcomes out of 10, so

P(8,9 or 10) = 3/10

H. Pr(greater than 9)

there is only one successful outcome, namely "10" out of 10 possible outcomes.  So

P(greater than 9) = P(10) = 1/10

1. please explain what’s a “die” all I know was “dice” but dice is 6 sided yea?

A die is singular for dice, which can take up any number of faces.  With a 10-faced solid, we can make a 10-faced die numbered 1 to 10.

2. and please explain the answer... I’m international student so I still need some explanation for the questions and answers thank you

See solutions above.

Answer:

Remember that standard probabilities are defined as the ratio between the number of favorable cases, and the total number of possible events.

In this case, we have a 10-sided die, which means its faces are numbered from 1 to 10, which gives us 10 total number of possible events. In other words, the denominator of the ratio is going to be 10.

Now we're able to find each probability.

[tex]P_{8} =\frac{1}{10}=0.10[/tex]

The numerator is 1 because there's only one number 8 in the die, that means the number of favorable cases is 1, and, as we said before, the total number of possible events is 10.

[tex]P_{odd} =\frac{5}{10}=0.5[/tex]

The numerator is 5 because there are 5 odd numbers from 1 to 10. In other words, there are 5 favorable cases to this probability.

[tex]P_{even}=\frac{5}{10}=0.5[/tex]

There are 5 even numbers from 1 to 10, that's why we had the same probability.

We know that there are only 5 numbers less than 6 for this die.

[tex]P_{<6}=\frac{5}{10}=0.5[/tex]

A prime number is such that it can be divided only by itself and the unit. So, there are four prime numbers from 1 to 10, which are 2, 3, 5, 7.

[tex]P_{prime}=\frac{4}{10}=0.4[/tex]

When we are going to find the probability of an event "or" another, we must sum those favorable cases.

[tex]P_{3 \ or \ 8} =\frac{1+1}{10}=\frac{2}{10}=0.2[/tex]

In this case, we need to some all three favorable cases. The die has only one 8, one 9 and one 10. So, the probability is

[tex]P_{8,9,10}=\frac{1+1+1}{10}=\frac{3}{10} =0.3[/tex]

We know that there's only one number greater than 10 on such die.

[tex]P_{>10}=\frac{1}{10}=0.1[/tex]

Lastly, "die" refers to this special 10-sided dice. In other problems, you can find "a die" with more faces even. But, in general, "die" refers to a dice.

Answer:

The difference in their wages is because the quantity of output produced by a unit of labor is higher for a cook than a dishwasher and also because Bruno is an unskilled labor while Charlie can be categorised as a semiskilled labor.

Step-by-step explanation:

Bruno is a dishwasher

Charlie is a cook

Bruno earnings=$x

Charlie earns $2 more than his twin Bruno

Charlie earnings= $x+2.00

At the same restaurant for an hourly rate

The difference in the wages of Bruno and Charlie is as a result of the productivity of labor

The quantity of output produced by a unit of labor is higher for a cook than a dishwasher and also because Bruno is an unskilled labor while Charlie can be categorised as a semiskilled labor.

Answer:

Area of the triangle = 0

Step-by-step explanation:

We are given the vertices of a triangle as: (- 8,4 ), (- 6,6), (- 3,9)​

The formula to find the Area of the triangle =

1/2[ x₁(y₂ - y₃) + x₂(y₃ - y₁) + x₃(y₁ - y₂)]

Where :

(x₁, y₁) =  (- 8,4 )

(x₂, y₂) = (- 6,6)

(x₃, y₃) =  (- 3,9)

Area of the triangle = 1/2[-8(6 - 9) + -6(9 - 4) + -3(4 - 6)]

= 1/2[ (-8 × -3) +( -6 × 5) +( -3× -2)]

= 1/2[ 24 - 30 + 6)

= 1/2[ 24 + 6 - 30]

= 1/2 [30 - 30]

=1/2[ 0 ]

= 0

Therefore, the area of triangle whose vertices are (- 8,4 ), (- 6,6) and (- 3,9)​ is ZERO( = 0 )

Answer:

C

Step-by-step explanation:

The required graph has been attached below which shows the boat's value decreasing at a rate of 40% per year.

A graph can be defined as a pictorial representation or a diagram that represents data or values.

A boat's value over time is given as the function f(x) and graphed below.  A(x) = 400(b)ˣ + 0 as the parent function.

Given that the boat's value decreases at a rate of 40% per year.

So after each year, the value becomes = 1 - 40% = 1 - 0.40 = 0.60 of the previous year.

So the equation becomes: A(x) = 400(0.60)ˣ + 0

Since, b = 0.60 < 1, so A(x) is a decreasing function. And for every value of x, A(x) > 0.

The attached graph meets these requirements.

Learn more about the graphs here:

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Answer:

x = 45

Step-by-step explanation:

Since ray IK║EH and IG is a transverse,

∠GIK ≅ ∠IGF [Corresponding angles]

Therefore, m∠IGF = x

Since, m∠JIF + m∠GIF = 180° [Supplementary angles]

2x + m∠GIF = 180°

m∠GIF = (180 - 2x)

Similarly, m∠IFE + m∠IFG = 180°

3x + m∠IFG = 180°

m∠IFG = (180 - 3x)

By the property of a triangle,

"Sum of all interior angles of a triangle is 180°"

m∠IGF + m∠GFI + m∠FIG = 180°

x° + (180 - 2x)° + (180 - 3x)° = 180°

(x - 2x - 3x) + 360 = 180

-4x + 360 = 180

4x = 360 - 180

4x = 180

x = 45

Answer:

Anna's wand can cast 70 spells

Step-by-step explanation:

Elsa's wand can cast 53 spells

her wand casts 17 fewer cells than her sister Anna's

Amount of spells cast by Anna's wand = ?

We write the question down in the form of an equation

[tex]x - 17 = 53[/tex]

where [tex]x[/tex] is the amount of spells Anna's wand can cast.

we then proceed to solve by collecting like terms to different sides of the equation. We'll have

[tex]x = 53 + 17[/tex]

which leaves us with

[tex]x = 70[/tex]

This means that Anna's wand can cast 70 spells.

Answer: $8

Step-by-step explanation: $120+10%=$132. $140-$132=$8.

Answer:

The total number of dots on the 200th triangle is 603

Step-by-step explanation:

Please check the attachment for the diagram of the triangular dots that completes the question

From the diagram, we can see that the first triangle has 6 total dots, second has 9 total dots, third has 12 total dots;

This shows a arithmetic progression pattern of the triangles where we have our first term being 6, with our common difference being the number of dots increment on all sides as we progress which is 3

Now we want to calculate for the 200th triangle

Mathematically, the nth term of an arithmetic sequence is given as;

Tn = a + (n-1)d

where a = 6 , d = 3 and n = 200

Substituting these values in the equation above, we have

Tn = 6 + (200-1)3

Tn = 6 + 199(3)

Tn = 6 + 597

Tn = 603

Answer:

86

Step-by-step explanation:

We can set the first digit as (10x+y)

We can interchange it to be (10y+x)

X is the second digit and Y is the first.

1) (10x+y) +(10y+x) =154

2) 11x+11y=154

3) 11(x+y) =154

4) x+y=14

5) x+x+2=14

6) 2x=12

7) x=6

8) y=6+2=8 , so y =8