Answer:
A sample size of 2080 is needed.
Step-by-step explanation:
In a sample with a number n of people surveyed with a probability of a success of [tex]\pi[/tex], and a confidence level of [tex]1-\alpha[/tex], we have the following confidence interval of proportions.
[tex]\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
In which
z is the zscore that has a pvalue of [tex]1 - \frac{\alpha}{2}[/tex].
The margin of error is:
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
98% confidence level
So [tex]\alpha = 0.02[/tex], z is the value of Z that has a pvalue of [tex]1 - \frac{0.02}{2} = 0.99[/tex], so [tex]Z = 2.327[/tex].
Based on previous evidence, you believe the population proportion is approximately 60%.
This means that [tex]\pi = 0.6[/tex]
How large of a sample size is required?
We need a sample of n.
n is found when [tex]M = 0.025[/tex]. So
[tex]M = z\sqrt{\frac{\pi(1-\pi)}{n}}[/tex]
[tex]0.025 = 2.327\sqrt{\frac{0.6*0.4}{n}}[/tex]
[tex]0.025\sqrt{n} = 2.327\sqrt{0.6*0.4}[/tex]
[tex]\sqrt{n} = \frac{2.327\sqrt{0.6*0.4}}{0.025}[/tex]
[tex](\sqrt{n})^{2} = (\frac{2.327\sqrt{0.6*0.4}}{0.025})^{2}[/tex]
[tex]n = 2079.3[/tex]
Rounding up
A sample size of 2080 is needed.
find the value of a. A: 15, B: 19
Answer:
A: 15
Step-by-step explanation:
The angles are opposite to each other.
Vertically opposite angles are equal in size.
Put up an equation and solve for a.
6a + 10 = 3a + 55
Subtract 3a and 10 on both sides.
6a - 3a = 55 - 10
Combining like terms.
3a = 45
Divide both sides by 3.
a = 45/3
a = 15
The value of a is 15.
Answer:
a = 15
Step-by-step explanation:
=> 6a + 10 = 3a + 55 (Vertically Opposite Angles are congruent)
Combining like terms
=> 6a - 3a = 55 - 10
=> 3a = 45
Dividing both sides by 3
=> a = 15
Subtracting polynomials
Answer:
The third side of the triangle is 10x + 3
Step-by-step explanation:
x + 1 + 2x + 4 = 3x + 5
( 13x + 8 ) - ( 3x + 5 ) = 13x + 8 - 3x - 5
= 10x + 3
There are two frozen yogurt stores in the mall. Both stores sell frozen yogurt by the ounce. Hammy's Froyo charges $2.40 for the container and $0.40 for each ounce of yogurt. Yogurt Palace charges $0.80 for each ounce of yogurt (no charge for the container). Graph the line that shows the cost of frozen yogurt at Hammy's Froyo. Graph the line that shows the cost of frozen yogurt at Yogurt Palace.
Answer:
The graphs for the lines of the costs are in the attachment. For this answer you have to first determine the equations for each cost. Since Hammy's Froyo charges $2.40 for the container and $.40 for each ounce, the equation would be y=.40x+2.40. For Yogurt Palace, which charges $0.80 for each ounce, the equation would be y=.80x.
Find a power series for the function, centered at c. f(x) = 1 9 − x , c = 4 f(x) = [infinity] n = 0 Incorrect: Your answer is incorrect. Determine the interval of convergence. (Enter your answer using interval notation.)
Looks like the given function is
[tex]f(x)=\dfrac1{9-x}[/tex]
Recall that for |x| < 1, we have
[tex]\displaystyle\frac1{1-x}=\sum_{n=0}^\infty x^n[/tex]
We want the series to be centered around [tex]x=4[/tex], so first we rearrange f(x) :
[tex]\dfrac1{9-x}=\dfrac1{5-(x-4)}=\dfrac15\dfrac1{1-\frac{x-4}5}[/tex]
Then
[tex]\dfrac1{9-x}=\displaystyle\frac15\sum_{n=0}^\infty\left(\frac{x-4}5\right)^n[/tex]
which converges for |(x - 4)/5| < 1, or -1 < x < 9.
Over what interval is the function in this graph increasing?
5
-6
-5
Determine if the field Bold Upper F equals 10 yz Bold i plus 10 xz Bold j plus 10 xy Bold k is conservative or not conservative.
F is conservative if we can find a scalar funciton f such that grad(f) = F.
This would entail
[tex]\dfrac{\partial f}{\partial x}=10yz[/tex]
[tex]\dfrac{\partial f}{\partial y}=10xz[/tex]
[tex]\dfrac{\partial f}{\partial z}=10xy[/tex]
Integrate both sides of the first equation with respect to x :
[tex]f(x,y,z)=10xyz+g(y,z)[/tex]
Differentiate both sides with respect to y :
[tex]\dfrac{\partial f}{\partial y}=10xz=10xz+\dfrac{\partial g}{\partial y}[/tex]
[tex]\implies\dfrac{\partial g}{\partial y}=0\implies g(y,z)=h(z)[/tex]
Differentiate both sides with respect to z :
[tex]\dfrac{\partial f}{\partial z}=10xy=10xy+\dfrac{\mathrm dh}{\mathrm dz}[/tex]
[tex]\implies\dfrac{\mathrm dh}{\mathrm dz}=0\implies h(z)=C[/tex]
So we have
[tex]f(x,y,z)=10xyz+C[/tex]
that satisfies
[tex]\nabla f(x,y,z)=\mathbf F(x,y,z)[/tex]
and so F is indeed conservative.
Dimitri is solving the equation x2 – 10x = 21. Which value must be added to both sides of the equation to make the left side a perfect-square trinomial?
Answer:
[tex]\boxed{\sf \ \ 25 \ \ }[/tex]
Step-by-step explanation:
Hello,
we can see that
[tex]x^2-10x = x^2-2*5x[/tex]
is the beginning of
[tex]x^2-2*5x+5^2=(x-5)^2[/tex]
so we must add 5*5=25 to both sides of the equation to make the left side a perfect square trinomial
hope this helps
Answer:
25.
Step-by-step explanation:
To find the value that will make the left side a perfect-square trinomial, you need to find (b/2)^2. In this case, b = -10.
(-10 / 2)^2
= (-5)^2
= (-5) * (-5)
= 25
Once you add 25 to both sides, the left side becomes x^2 - 10x + 25, which is equal to (x - 5)^2.
Hope this helps!
solve the rational equation 5/x = 4x+1/x^2
Answer:
x = 1
Step-by-step explanation:
Set up the rational expression with the same denominator over the entire equation.
Since the expression on each side of the equation has the same denominator, the numerators must be equal
5x =4x+1
Move all terms containing x to the left side of the equation.
Hope this can help you
Limit of f(t) as t approaches 0. f(t) = (t sin(t)) ÷ (1-cos(t))
Recall the Pythagorean identity,
[tex]1-\cos^2t=\sin^2t[/tex]
To get this expression in the fraction, multiply the numerator and denominator by [tex]1+\cos t[/tex]:
[tex]\dfrac{t\sin t}{1-\cos t}\cdot\dfrac{1+\cos t}{1+\cos t}=\dfrac{t\sin t(1+\cos t)}{\sin^2t}=\dfrac{t(1+\cos t)}{\sin t}[/tex]
Now,
[tex]\displaystyle\lim_{t\to0}\frac{t\sin t}{1-\cos t}=\lim_{t\to0}\frac t{\sin t}\cdot\lim_{t\to0}(1+\cos t)[/tex]
The first limit is well-known and equal to 1, leaving us with
[tex]\displaystyle\lim_{t\to0}(1+\cos t)=1+\cos0=\boxed{2}[/tex]
You work at a coffee house. Roasted coffee beans retain approximately 3/5 of their initial weight. Approximately what percent of their inital weight do they retain?
Answer:
60%
Step-by-step explanation:
We need convert 3/5 into a percent in order to find the answer.
We can convert by first dividing 3 by 5 to find the decimal value.
3/5= .6
Now we need to multiply by 100 to make it a percentage
.6 x 100= 60
60%
please I need help with this question!
The weight of adult males in Boston are normally distributed with mean 69 kilograms and variance 25 kilograms.
I. what percentage of adult male in Boston weigh more than 72 kilograms?
ii. what must an adult male weigh in order to be among the heaviest 10% of the population?
Thank you in advance!
Answer:
I. 60%
II. 75.4 kg
Step-by-step explanation:
We will use the z-scores and the standard normal distribution to answer this questions.
We have a normal distribution with mean 69 kg and variance 25 kg^2 (therefore, standard deviation of 5 kg).
I. What percentage of adult male in Boston weigh more than 72 kg?
We calculate the z-score for 72 kg and then calculate the associated probability:
[tex]z=\dfrac{X-\mu}{\sigma}=\dfrac{72-69}{5}=\dfrac{3}{5}=0.6\\\\\\P(X>72)=P(z>0.6)=0.274[/tex]
II. What must an adult male weigh in order to be among the heaviest 10% of the population?
We have to calculate tha z-score that satisfies:
[tex]P(z>z^*)=0.1[/tex]
This happens for z=1.28 (see attachment).
Then, we can calculate the weight using this transformation:
[tex]X=\mu+z^*\cdot\sigma=69+1.28\cdot 5=69+6.4=75.4[/tex]
Please help a girl out !!!!
Answer:
work is shown and pictured
X 2.3.3-PS
A planet has a surface temperature of 803° Fahrenheit. What is this temperature in degrees Celsius?
The formula used to convert from Fahrenheit (F) to Celsius (C) is
(Use integers or fractions for any numbers in the equation.)
Answer:
Celcius=( farenheit -32)*5/9
Celcius temperature is= 428.3333°
Step-by-step explanation:
To convert for farenheit to celcius
Celcius=( farenheit -32)*5/9
To calculate a temperature from celcius to farenheit we multiply by 9/5 and then add 32.
Let x be the celcius temperature
X(9/5) + 32 = 803°
X(9/5) = 803-32
X(9/5) = 771
X=( 771*5)/9
X= 3885/9
X= 428.3333
NEED HELP AS SOON AS POSSIBLE which interval describes where the graph of the function is negative
Answer:
2 < x < ∞
Step-by-step explanation:
We want where the value of y is less than zero
The value of the graph is less than zero is from x=2 and continues until x = infinity
2 < x < ∞
Answer:
[tex]\boxed{2 < x < \infty}[/tex]
Step-by-step explanation:
The value of y should be less than 0 for the graph of the function to be negative.
In the graph, when it startes from x is 2 the value becomes less than 0 and it keeps continuing until x is equal to infinity.
[tex]2 < x < \infty[/tex]
About 9% of the population has a particular genetic mutation. 600 people are randomly selected.
Find the standard deviation for the number of people with the genetic mutation in such groups of 600.
Answer:
The mean for all such groups randomly selected is 0.09*800=72.
Step-by-step explanation:
The value of the standard deviation is 7.
What is the standard deviation?Standard deviation is defined as the amount of variation or the deviation of the numbers from each other.
The standard deviation is calculated by using the formula,
[tex]\sigma = \sqrt{Npq}[/tex]
N = 600
p = 9%= 0.09
q = 1 - p= 1 - 0.09= 0.91
Put the values in the formulas.
[tex]\sigma = \sqrt{Npq}[/tex]
[tex]\sigma = \sqrt{600 \times 0.09\times 0.91}[/tex]
[tex]\sigma[/tex] = 7
Therefore, the value of the standard deviation is 7.
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The Stanford-Binet Intelligence Scale is an intelligence test, which, like many other IQ tests, is standardized in order to have a normal distribution with a mean of 100 and a standard deviation of 15 points.
As an early intervention effort, a school psychologist wants to estimate the average score on the Stanford-Binet Intelligence Scale for all students with a specific type of learning disorder using a simple random sample of 16 students with the disorder. Determine the margin of error, m, of a 99% confidence interval for the mean IQ score of all students with the disorder. Assume that the standard deviation IQ score among the population of all students with the disorder is the same as the standard deviation of IQ score for the general population, sigma = 15 points.
Answer:
The margin of error is [tex]MOE = 9.68[/tex]
Step-by-step explanation:
From the question we are told that
The sample size is [tex]n= 16[/tex]
The standard deviation is [tex]\sigma = 15[/tex]
The confidence level is [tex]C = 99[/tex]%
Generally the level of significance is mathematically evaluated as
[tex]\alpha = 100 - C[/tex]
[tex]\alpha = 100 - 99[/tex]
[tex]\alpha = 1%[/tex]%
[tex]\alpha = 0.01[/tex]
The critical value of [tex]\frac{\alpha }{2}[/tex] obtained from the normal distribution table is
[tex]Z_{\frac{\alpha }{2} } = 2.58[/tex]
The reason obtaining the critical value of [tex]\frac{\alpha }{2}[/tex] instead of [tex]\alpha[/tex] is because we are considering the two tails of the area normal distribution curve which is not inside the 99% confidence interval
Now the margin of error is evaluated as
[tex]MOE = Z_{\frac{\alpha }{2} } * \frac{\sigma}{\sqrt{n} }[/tex]
substituting values
[tex]MOE = 2.58 * \frac{15}{\sqrt{16} }[/tex]
[tex]MOE = 9.68[/tex]
What scenario depicts two independent events
Step-by-step explanation:
A t
eacher is calling on students to present their reports. He calls on Mario first and then chooses the next presenter from the remaining students. The girls’ basketball team is playing against the boys’ basketball team. The coach chooses a captain for the girls’ team and then chooses a captain for the boys’ team. Yasmin is picking flowers from a garden to create a bouquet. She picks a flower, keeps it for the bouquet, and then she picks another. Felipe is making a dentist appointment. First he chooses the day for his appointment, and then he chooses the time from the available openings.
Answer:
A.The school play opens tonight and it is raining.
B.Neva is hungry and she buys a snack from the concession stand.
C. Ari chooses a partner for a group project and then Ezekial chooses a partner from the remaining classmates.
D.Luka paints during school and he stains his shirt.
A certain virus infects one in every 400 people. A test used to detect the virus in a person is positive 80% of the time if the person has the virus and 10% of the time if the person does not have the virus. (This 10% result is called a false positive.) Let A be the event "the person is infected" and B be the event "the person tests positive".
(a) Using Bayes’ Theorem, when a person tests positive, determine the probability that the person is infected.
(b) Using Bayes’ Theorem, when a person tests negative, determine the probability that the person is not infected.
Answer:
A) P(A|B) = 0.01966
B) P(A'|B') = 0.99944
Step-by-step explanation:
A) We are told that A is the event "the person is infected" and B is the event "the person tests positive".
Thus, using bayes theorem, the probability that the person is infected is; P(A|B)
From bayes theorem,
P(A|B) = [P(A) × P(B|A)]/[(P(A) x P(B|A)) + (P(A') x P(B|A'))]
Now, from the question,
P(A) = 1/400
P(A') = 399/400
P(B|A) = 0.8
P(B|A') = 0.1
Thus;
P(A|B) = [(1/400) × 0.8)]/[((1/400) x 0.8) + ((399/400) x (0.1))]
P(A|B) = 0.01966
B) we want to find the probability that when a person tests negative, the person is not infected. This is;
P(A'|B') = P(Not infected|negative) = P(not infected and negative) / P(negative) = [(399/400) × 0.9)]/[((399/400) x 0.9) + ((1/400) x (0.2))] = 0.99944
the substitution method solve 6x-y=3 4x+3y=1
Answer:
[tex]( \frac{5}{11} \:, - \frac{3}{11} )[/tex]Step-by-step explanation:
6x - y = 3
4x + 3y = 1
Solve the equation for y
y = -3 + 6x
4x + 3y = 1
Substitute the given value of y into the equation
4x + 3y = 1
plug the value
[tex]4x + 3( - 3 + 6x) = 1[/tex]
Distribute 3 through the parentheses
[tex]4x - 9 + 18x = 1[/tex]
Collect like terms
[tex]22x - 9 = 1[/tex]
Move constant to R.H.S and change its sign
[tex]22x = 1 + 9[/tex]
Calculate the sum
[tex]22x = 10[/tex]
Divide both sides of the equation by 22
[tex] \frac{22x}{22} = \frac{10}{22} [/tex]
Calculate
[tex]x = \frac{5}{11} [/tex]
Now, substitute the given value of x into the equation
y = -3 + 6x
[tex]y = - 3 + 6 \times \frac{5}{11} [/tex]
Solve the equation for y
[tex]y = - \frac{3}{11} [/tex]
The possible solution of the system is the ordered pair ( x , y )
[tex](x ,\: y) = ( \frac{5}{11} ,\: - \frac{3}{11} )[/tex]-----------------------------------------------------------
Check if the given ordered pair is the solution of the system of equations
[tex]6 \times \frac{5}{11} - ( - \frac{3}{11} ) = 3[/tex]
[tex]4 \times \frac{5}{11 } + 3 \times ( - \frac{3}{11} ) = 1[/tex]
Simplify the equalities
[tex] 3 = 3[/tex]
[tex]1 = 1[/tex]
Since all of the equalities are true , the ordered pair is the solution of the system
[tex]( \: x ,\: y \: ) = ( \frac{5}{11} \:, - \frac{3}{11} )[/tex]Hope this helps..
Best regards!!
it takes olivia one minute to swim 1/60 of a kilometer how far can she swim in 12 minutes
Answer:
1/5 if a kilometer
Step-by-step explanation:
Since it was 1/60 of a kilometer which is 0.0166 of the kilometer.
So In 12 minutes he would cover 0.2 of the kilometer which is 1/5
The distance Olivia swims in 2 minutes is 1/30 km.
Given,
It takes Olivia one minute to swim 1/60 of a kilometer.
We need to find out how far can she swim in 12 minutes.
How to compare two units in proportion?Suppose if we have,
3 items cost = $9
Cost of one item = $9 / 3 = $3
If in 5 minutes one can walk for 1km
In 10 minutes one can walk:
= (10/5 x 1) km
= 2 km
Find the distance Olivia swims in one minute.
= 1/60 km
Find the distance Olivia swims in 2 minutes.
We have,
1 minute = 1/60 km
Multiply both sides by 2.
2 x 1 minute = 2 x 1/60 km
2 minutes = 1/30 km
Thus the distance Olivia swims in 2 minutes is 1/30 km.
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Solve for x: [X - 3] + [x + 5]= 10
Answer:
x = 4Step-by-step explanation:
[X - 3] + [x + 5]= 10
Remove the parenthesis
That's
x - 3 + x + 5 = 10
Simplify
2x + 2 = 10
2x = 10 - 2
2x = 8
Divide both sides by 2
x = 4Hope this helps you
Suppose , varies jointly with g and v, and j = 2 when g = 4 and v= 3.
Find j when g = 8 and v= 11.
Answer:
j = 44/3
Step-by-step explanation:
j varies jointly as g and v. This can be represented mathematically as:
[tex]j \alpha gv\\j = kgv[/tex].............(1)
Where k is a constant of proportionality
j = 2 when g = 4 and v = 3
Substitute these values into equation (1)
2 = k * 4 * 3
2 = 12 k
k = 1/6
when g = 8 and v = 11:
j = (1/6) * 8 * 11
j = 44/3
Gabriella drives her car 360 miles and averages a certain speed, If the average speed had been 6 mph less, she could have traveled only 330 miles in the same length of time. What is her average speed?
Answer:
72mile/hr
Step-by-step explanation:
Let d be distance in mile
Let r be average rate in mile/hr
Let t be time in hr
d = r × t
t = d/r
360/r = t ........1
Also
The question stated that the average speed was 6 less to travel a distance of 330mile at the same time.
Since the average speed is r, hence 6 less that r = r-6 at the same time
Therefore
330/r-6 = same time ( t ) .......2
Equate 1 and 2
360/r = 330/r-6
Cross multiply
360(r-6) = 330(r)
360r - 360×6 = 330r
360r - 2160 = 330r
Collecting like terms
- 2160 = 330r - 360r
- 2160 = - 30r
Divide both sides by - 30
- 2160/ - 30 = - 30r/ - 30
r = 72mile/hr
Hence the average speed is 72mile/hr
HELP!!! Evaluate 8^P7
The correct answer is B. 40,320
Explanation:
In mathematics, a permutation refers to all the possible ways of arranging objects or elements in a set, while still considering an order. For example, you can calculate all the possible ways 5 athletes can end in a race as one athlete cannot have both the first and third place. The expression [tex]{8}[/tex][tex]P_{7}[/tex] shows a permutation because the P indicates the expression refers to a permutation. Additionally, this can be solved by using the formula [tex]{n}[/tex][tex]P_{r}[/tex] =[tex]\frac{n!}{(n-r)!}[/tex]. This means, in the expression presented n = 8 while r = 7. Also, the symbol (!) indicates the number should be multiplied using all whole numbers minor to the given number until you get to 1, which is known as factorial functions. The process is shown below:
[tex]{n}[/tex][tex]P_{r}[/tex] =[tex]\frac{n!}{(n-r)!}[/tex] [tex]{8}[/tex][tex]P_{7}[/tex] = [tex]\frac{8!}{(8-7) !}[/tex][tex]{8}[/tex][tex]P_{7}[/tex] = [tex]\frac{8!}{1!}[/tex][tex]{8}[/tex][tex]P_{7}[/tex] = [tex]\frac{8 x 7 x 6 x 5 x 4 x 3 x 2 x 1}{1}[/tex] or 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 / 1
[tex]{8}[/tex][tex]P_{7}[/tex] = 40320
If a line with the slope of -1 goes through the point (-2,-2), then solve for b: y=mx+b
Answer:
b = -4
Step-by-step explanation:
Well we already have m which is slope which is -1.
And if we start at (-2,-2) and go down using the slope we get -4 as the y intercept or b.
Thus,
-4 is the y intercept or b.
Hope this helps :)
Answer:
b = -4.
Step-by-step explanation:
In this case, y = -2, m = -1, and x = -2.
-2 = (-1) * (-2) + b
-2 = 2 + b
b + 2 = -2
b = -4
Hope this helps!
Suppose that your uncle is decorating his house for christmas.He uses 300 strands of lights each containing 150 light bulbs.Each light bulb consumes 4 watts of power. If he illuminates his light for 5 hours a day for 30 days and power in his area sells for $0.08/kWh, how much will he end up paying to light his home for the holidays?
Answer:
$14.4
Step-by-step explanation:
From the question;
There are 300 strands of light each containing 150 light bulbs. Altogether, there are;
300 x 150 light bulbs = 45000 light bulbs.
Also;
Each bulb consumes 4 watts of power. Since there are 45000 light bulbs, the total power consumed by all the bulbs is;
45000 x 4 watts = 180000watts
Next convert the total power consumed to kW by dividing by 1000. i.e
180000watts = 180kW
Therefore, total power consumed is 180kW
He lights up for 5 hours a day for 30 days. This means that the total number of hours he lights his home for those 30 days is:
30 x 5 hours = 150 hours.
Now since power in his area sells for $0.08/kWh, this means that;
1kWh costs $0.08
Then;
180kWh will cost [180kWh x $0.08 / 1kWh] = $14.4
Therefore, he will end up paying $14.4 to light his home for the holidays.
A hypothesis will be used to test that a population mean equals 9 against the alternative that the population mean is less than 9 with known variance . What is the critical value for the test statistic for the significance level of 0.020
Answer:
-2.05
Step-by-step explanation:
From the given information,
Let consider [tex]\mu[/tex] to represent the population mean
Therefore,
The null and alternative hypothesis can be stated as :
[tex]H_o :\mu=9[/tex]
[tex]H_1 :\mu<9[/tex]
From the hypothesis , the alternative hypothesis is one tailed (left)
when the level of significance = 0.020, the Z- critical value can be determined from the standard normal distribution table
Hence, the Z-critical value at ∝ = 0.020 is -2.05
.If you add 5 to both the numerator and the denominator of a fraction, you obtain 2/3; however, if '
you subtract 5 from both the numerator and the denominator of the same fraction, you obtain 1/4. For what fraction is this true?
Answer:
The fraction that this is true for = 7/13
Step-by-step explanation:
From the above question
Let the numerator be represented by a
Let the denominator be represented by b
If you add 5 to both the numerator and the denominator of a fraction, you obtain 2/3
This means:
a + 5/b + 5 = 2/3
Cross Multiply
3(a + 5) = 2(b + 5)
3a + 15 = 2b + 10
Collect like terms
3a - 2b = 10 - 15
3a - 2b = -5..........Equation 1
If you subtract 5 from both the numerator and the denominator of the same fraction, you obtain 1/4
This means:
a - 5/b - 5 = 1/4
Cross Multiply
4(a - 5) = 1(b - 5)
4a - 20 = b - 5
Collect like terms
4a - b = 20 - 5
4a - b = 15..........Equation 2
b = 4a - 15
3a - 2b = -5..........Equation 1
4a - b = 15..........Equation 2
Substitute 4a - 15 for b in equation 1
3a - 2b = -5..........Equation 1
3a - 2(4a - 15) = -5
3a - 8a + 30 = -5
Collect like terms
3a - 8a = -5 - 30
-5a = -35
a = -35/-5
a = 7
Therefore, the numerator of the fraction = 7
Substitute 7 for a in Equation 2
4a - b = 15..........Equation 2
4 × 7 - b = 15
28 - b =15
28 - 15 = b
b = 13
The denominator = b is 13.
Therefore,the fraction which this is true for = 7/13
To confirm
a) If you add 5 to both the numerator and the denominator of a fraction, you obtain 2/3
This means:
a + 5/b + 5 = 2/3
7 + 5/ 13 + 5 = 2/3
12/18 = 2/3
Divide numerator and denominator by of the left hand side by 6
12÷ 6/ 18 ÷ 6 = 2/3
2/3 =2/3
If you subtract 5 from both the numerator and the denominator of the same fraction, you obtain 1/4
This means:
a - 5/b - 5 = 1/4
7 - 5/13 - 5 = 1/4
2/8 = 1/4
Divide the numerator and denominator of the left hand side by 2
2÷2/8 ÷ 2 = 1/4
1/4 = 1/4
From the above confirmation, the fraction that this is true for is 7/13
WILL MARK BRAINLIEST If Alan and Zack can clean a room in 30 minutes when working together, and Alan cleans twice as fast as Zack, how long would it take Alan to clean the room by himself?
Answer:
45 min
Step-by-step explanation:
Here,
the we take the work as W and Alan's speed as A and Zack's speed as Z.
A = 2Z
W = 30 ( A+Z)
if the time for Alan to done cleaning alone is t then t = W ÷ A
t = ( 30 (A+(A÷2)))÷ A
t = 45 min
I am done .
About 30% of babies born with a certain ailment recover fully. A hospital is caring for five babies born with this ailment. The random variable represents the number of babies that recover fully. Decide whether the experiment is a bnomial experiment. If it is identify a success, specify the values of n,p, and q and list the possible values of hte random variable x.
1. Specigy the value of n. Select the correct choice bellow and fill in any answer boxes in your choice.
A. n=
B. This is not a binomial experiment
2. Specify the value of p. Select the correct choice below and fill in any answer boxes in your choice
A p=
B. This is not a binomial experiment.
3. Specify the value of q. Select the correct choice below and fill in any answer boxes in your choice.
A. q=
B. This is not a binomial experiment
Answer:
n = 5 (a)p = 0.3 (a)q = 0.7 (a)Step-by-step explanation:
From the Given data in the above question it can be said that the experiment is a Binomial experiment because there is a success rate and a failure rate involved and the success rate is about 30% of the babies recovering from the ailment while the failure rate is about 70% of the babies not recovering from the ailment
The number of babies (n) = 5
success rate (p) = 30% = 0.3
failure rate (q) = 100% - 30% = 70% = 0.7
The possible values of the random value x = from 0 to 5