Question 4 (20 Points): A marketing survey is to be planned to estimate the proportion of all customers who would subscribe to a new pay-per-view service that a cable TV plans to offer. The sample size for the survey is to be decided to estimate this proportion within a margin of error 2 percentage of points using a 95% confidence interval.
a) If the a priori guess of the proportion was 20%. What sample size should be used? (10 pts.)
If no a priori guess of the proportion was available, what sample size should be used? Why is this sample size larger than that found in part (a)? (10 pts.)

a) If the a priori guess of the proportion was 20%. What sample size should be used? (10 pts.)

The sample size formula uses three key factors:
(1) the alpha level, the level of acceptable risk the researcher is willing to accept that the true margin of error exceeds the acceptable margin of error; i.e., the probability that differences revealed by statistical analyses really do not exist; also known as Type I error.

The alpha level used in determining sample size in this survey is.05. In the formula, the alpha level is incorporated into the formula by utilizing the t-value for the alpha level ...

Solution Summary

Question 4 (20 Points): A marketing survey is to be planned to estimate the proportion of all customers who would subscribe to a new pay-per-view service that a cable TV plans to offer. The sample size for the survey is to be decided to estimate this proportion within a margin of error 2 percentage of points using a 95% confidence interval.
a) If the a priori guess of the proportion was 20%. What sample size should be used? (10 pts.)
If no a priori guess of the proportion was available, what sample size should be used? Why is this sample size larger than that found in part (a)? (10 pts.)

People end up tossing 12% of what they buy at the grocery store. Assume this is the true population proportion and that you plan to take a sample survey of 540 grocery shoppers to further investigate their behavior.
a. What is the probability that your survey will provide a sample proportion between 0.09 and 0.15?
b. What is

A survey of 705 workers asked how much they used the Internet at work. 423 said they used it within limits, and 183 said that they did not use the Internet at work. Construct a 95% confidence interval estimate for the proportion of all workers who use the Internet within limits.

According to the Pew Internet & American Life Project, 75% of American adults use the
Internet (Pew Internet website, April 19, 2008). The Pew project authors also reported on
the percentage ofAmericans who use the Internet by age group. The data in the file AgeGroup
are consistent with their findings. These data were obtaine

You plan to conduct a survey to find what proportion of the workforce has two or more jobs. You decide on the 95 percent confidence level and state that the estimated proportion must be within 2 percent of the population proportion. A pilot survey reveals that 5 of the 50 sampled hold two or more jobs. How many in the workforce

Based on its 1999 survey, Student Monitor reports that 20% of U.S. college students used the Internet for job hunting during the month preceding the survey. Assuming this finding to be based on a simple random sample of 1600 college students, construct an interpret the 90% confidence interval for the population proportion of col

17. A Louis Harris poll used a survey of 1008 adults to learn about how people feel about the economy (Business Week,August 7, 2000). Responses were as follows:
595 adults The economy is growing.
332 adults The economy is staying about the same.
81 adults The economy is shrinking.
Develop a point estimate of the follow

In response to media inquiries and concerns expressed by groups opposed to violence, the president of a university with over 25,000 students has agreed to survey a simple random sample of her students to find out whether the student body thinks the school's "Plundering Pirate" mascot should be changed to one that is less aggress

Question: In a survey of 842 musicians, 715 said they began playing an instrument while in elementary school.
Using Excel, construct a 90% confidence interval for the proportion of musicians who began playing an instrument while in elementary school.

Roper ASW conducted a survey to learn about American adults' attitudes toward money and happiness. 56% of the respondents said they balance their checkbook at least once a month.
a. Suppose a sample of 400 American adults were taken. Show the sampling distribution of the proportion of adults who balance their checkbook at le