Part I.
Suppose the coach of the football team wants to estimate the proportion of the population of fans who support his current starter lineup. The coach wants the estimate to be .04 of the true proportion. Assume a 99 percent level of confidence. The coach estimated the proportion supporting the current starter lineup to be .60.

Answer the following questions:

1. Construct a 99% confidence interval using a sample size of 50, then of 100, then of 1,000.
2. How did changing the sample size affect the size of the interval?
3. What is the error of the estimate for each of these sample sizes?
4. How large of a sample is required for the error of the estimate to be within +.04 of the population proportion?
5. How large would the sample have to be if the coach of the team were not available?

Show your work. Be prepared to present your analysis it to the class.

Part II.
A study is being done to determine how many hours college students study before taking an exam. A pilot study indicated that the mean time during the week of the exam is 4 hours, with a standard deviation of 1 hour. It is desired to estimate the mean study time within ½ hour. The 80 percent degree of confidence is to be used.

Answer the following question:

How many students should be surveyed?

Solution Summary

The solution calculates errors, confidence intervals and the effects of changing the sample size.

Part I.
Suppose the coach of the footballteam wants to estimate the proportion of the population of fans who support his current starter lineup. The coach wants the estimate to be .04 of the true proportion. Assume a 99 percent level of confidence. The coach estimated the proportion supporting the current starter lineup to

Suppose the President wants an estimate of the proportion of the population who support his current policy toward gun control. The President wants the estimate to be within 0.04 of the true proportion. Assume a 95% level of confidence. The President's political advisors estimated the proportion supporting the current policy t

An article reports that when each football helmet in a random sample of 44 suspension-type helmets was subjected to a certain impact test, 25 showed damage.
Let p denote the proportion of all helmets of this type that would show damage tested in the prescribed manner
Give your answers correct to three decimal places
Calcul

Many states are carefully considering steps that would help them collect sales taxes on items purchased through the Internet. How many randomly selected sales transactions must be surveyed to determine the percentage that transpired over the Internet? Assume that we want to be 99% confident that the sample percentage is within t

A market research agency would like to estimate the proportion of Canadian households owning a personal computer. What minimum samplesize will be required if they want to be 99% confident that the sampleproportion will not differ from the true population proportion by more than 5%?

Confidence Intervals andSampleSize
Part I
Suppose the coach of the footballteam wants to estimate the proportion of the population of fans who support his current starter lineup. The coach wants the estimate to be .04 of the true proportion. Assume a 95 percent level of confidence. The coach estimated the proportion

A poll of 1400 randomly selected students in grades 6 through 8 was conducted and found that 30% enjoy playing sports. Would confidence in the results increase if the samplesize were 3200 instead of 1400? Why or why not?

An automobile manufacturer would like to know what proportion of its customers are not satisfied with the service provided by the local dealer. The customer relations department will survey a random sample of customers and compute a 99% confidence interval for the proportion who are not satisfied.
(a) Past studies suggest t

For a sample of size n=100, proportion p = 0.6, and at a 95% confidence level, the upper bound of the proportion is:
A. 0.096
B. 0.696
C. 0.050
D. 0.025