Question: What proportion of people hit snags with online transactions? According to a poll conducted by Harris Interactive, 89% hit snags with online transactions ( Top Online Transaction Trouble, USA Today Snapshots, April 4, 2006, p. 1D).

a. To conduct a follow-up study that would provide 95% confidence that the point estimate is correct to within 0.04 of the population proportion, how large a sample size is required?

b. To conduct a follow-up study that would provide 99% confidence that the point estimate is correct to within 0.04 of the population proportion, how large a sample size is required?

c. To conduct a follow-up study that would provide 95% confidence that the point estimate is correct to within 0.02 of the population proportion, how large a sample size is required?

d. To conduct a follow-up study that would provide 99% confidence that the point estimate is correct to within ±0.02 of the population proportion, how large a sample size is required?

e. Discuss the effects of changing the desired confidence level and the acceptable sampling error on sample size requirements.