According to the National Retail Federation, 34% of taxpayers used computer software to do their taxes for the 2009 tax year. A sample of 125 taxpayers was selected.

a) Calculate the standard error of the proportion.

b) What is the probability that less than 30% of the taxpayers from the sample used computer software to do their taxes?

c) What is the probability that between 28% and 40% of the taxpayers from the sample used computer software to do their taxes?

d) What impact would changing the sample size to 225 taxpayers have on the results of parts a, b, and c?

7.36 At Goldey-Beacom College, 56% of employees carry dependent family members on their health insurance plans. Currently, there are 200 employees working for the college. A random sample of 50 employees is selected.

a) What is the probability that less than 60% of the sample carries dependent family members on their health insurance plan?

b) Answer the question in part a using sample sizes of 100 and 150. Explain the differences in these probabilities.

c) Answer the question in part a without the finite correction factor. Explain the differences in these probabilities