THis Is WaLtEr AnD i GiVe YoU 20 pOiNtS mErRy ChRiStMaS!!

A candidate for a US Representative seat from Indiana hires a polling firm to gauge her percentage of support among voters in he

UkoKoshka [18]

Answer:

a) The minimum sample size is 601.

b) The minimum sample size is 2401.

Step-by-step explanation:

In a sample with a number n of people surveyed with a probability of a success of $\pi$ , and a confidence level of $1-\alpha$ , we have the following confidence interval of proportions.

$\pi \pm z\sqrt{\frac{\pi(1-\pi)}{n}}$

In which

z is the zscore that has a pvalue of $1 - \frac{\alpha}{2}$ .

The margin of error is:

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

For this problem, we have that:

We dont know the true proportion, so we use $\pi = 0.5$ , which is when we are are going to need the largest sample size.

95% confidence level

So $\alpha = 0.05$ , z is the value of Z that has a pvalue of $1 - \frac{0.05}{2} = 0.975$ , so $Z = 1.96$ .

a. If a 95% confidence interval with a margin of error of no more than 0.04 is desired, give a close estimate of the minimum sample size that will guarantee that the desired margin of error is achieved. (Remember to round up any result, if necessary.)

This is n for which M = 0.04. So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.04 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.04\sqrt{n} = 1.96*0.5$

$\sqrt{n} = \frac{1.96*0.5}{0.04}$

$(\sqrt{n})^2 = (\frac{1.96*0.5}{0.04})^2$

$n = 600.25$

Rounding up

The minimum sample size is 601.

b. If a 95% confidence interval with a margin of error of no more than 0.02 is desired, give a close estimate of the minimum sample size necessary to achieve the desired margin of error.

Now we want n for which M = 0.02. So

$M = z\sqrt{\frac{\pi(1-\pi)}{n}}$

$0.02 = 1.96\sqrt{\frac{0.5*0.5}{n}}$

$0.02\sqrt{n} = 1.96*0.5$

$\sqrt{n} = \frac{1.96*0.5}{0.02}$

$(\sqrt{n})^2 = (\frac{1.96*0.5}{0.02})^2$

$n = 2401$

The minimum sample size is 2401.

4 0

3 years ago

What fraction is equal to 4/6

Rama09 [41]

4/6
= (4/2) / (6/2) (divide both numerator and denominator by 2)
= 2/3

The final answer is 2/3~

6 0

3 years ago

Find the value of x and y

hram777 [196]

Answer:

x = 12
y = 20

Step-by-step explanation:

There is nothing in this diagram to suggest any particular values for x and y.

__

If we assume the figure is intended to be a kite, symmetrical about its horizontal diagonal, then each segment is congruent to the one above it.

x = 12

y = 20

4 0

2 years ago

Please help i don’t understand

olganol [36]

9514 1404 393

Answer:

3

Step-by-step explanation:

Vertical angles share a vertex point, and have opposite rays for sides. In short, they are across the point of intersection from each other. Vertical angles do not have a common side (they are <em>not</em> adjacent).

The first part of the problem is to identify angle NCA. That is shown in red in the attachment. The vertical angle is across the point of intersection. It is angle 3.

5 0

3 years ago

Bruce drew a scale drawing of a restaurant. The scale he used was 1 millimeter 10 meters The restaurant's kitchen is 3 millimete

Burka [1]

Answer:

answer=30

Step-by-step explanation:

by taking the length as x

1 millimetre = 10 metres

3 millimetres = x

10×3= 30 metres

HOPE THIS HELPS

8 0

2 years ago