# Question: In May 2012 a Gallup Poll showed that 63 of

In May 2012, a Gallup Poll showed that 63% of randomly surveyed U.S. adults said the United States benefits from having a rich class. (The proportion was unchanged from 1990. The percentage was higher for Republicans than for Democrats.)

a. Assuming the sample size was 500, how many would have said that the United States benefits from having a rich class?

b. Is the sample size large enough to apply the Central Limit Theorem? Explain. Assume the other conditions for using the CLT are met.

c. Find a 95% confidence interval for the percent that believe the United States benefits from having a rich class, using the numbers from part a.

d. Find the width of the interval you found in part c by subtracting the lower boundary from the upper boundary.

e. Now assuming the sample size was multiplied by 9 (n = 4500) and the percentage was still 63%, how many would have said the United States benefits from having a rich class?

f. Find a 95% confidence interval, using the numbers from part e.

g. What is the width of the interval you found in part f?

h. When the sample size is multiplied by 9, is the width of the interval divided by 9? If not, what is it divided by?

a. Assuming the sample size was 500, how many would have said that the United States benefits from having a rich class?

b. Is the sample size large enough to apply the Central Limit Theorem? Explain. Assume the other conditions for using the CLT are met.

c. Find a 95% confidence interval for the percent that believe the United States benefits from having a rich class, using the numbers from part a.

d. Find the width of the interval you found in part c by subtracting the lower boundary from the upper boundary.

e. Now assuming the sample size was multiplied by 9 (n = 4500) and the percentage was still 63%, how many would have said the United States benefits from having a rich class?

f. Find a 95% confidence interval, using the numbers from part e.

g. What is the width of the interval you found in part f?

h. When the sample size is multiplied by 9, is the width of the interval divided by 9? If not, what is it divided by?

## Relevant Questions

Each student in a class of 40 was randomly assigned one line of a random number table. Each student then counted the odd-numbered digits in a 30-digit line. (Remember that 0, 2, 4, 6, and 8 are even.) a. On average, in the ...In the 2012 General Social Survey, people were asked whether they thought the sun went around the planet Earth or vice versa. Of 1974 people, 203 thought the sun went around Earth. a. What proportion of people in the survey ...A study was done of children from Malawi (in southeastern Africa) with severe acute malnutrition (Trehan et al. 2013). Of the 922 children randomized to receive amoxicillin in addition to food, 817 recovered. Of the 922 ...A poll on a proposition showed that we are 95% confident that the population proportion of voters supporting it is between 40% and 48%. Find the margin of error. Are the career goals of young men changing? A Pew Poll asked young men about the importance they place on having a high-paying career or profession. Those men who said being successful in a high-paying career is “one of ...Post your question