s AR NP Mt arLEIT KR MRENE frEs h | RS TEETES 8 W mmrmmmms EXERCISE (Confidence Interval for Proportion): Banking You wish to estimate, with 90% confidence, the population proportion of U.5. adults who are confident in the stability of the U.5. banking system. Your estimate must be accurate within 3% of the population proportion. a. No preliminary estimate is available, in other words, a pilot sample is not available. Find the minimum sample size needed. b. Find the minimum sample size needed, using a prior study that found that 43% of U.S. adults are confident in the stability of the U.5. banking system. c. Compare the results from parts (a) and (b). d. Verify the result from part (b) with PHStat. 17 EXERCISE (Confidence Interval for Proportion): Ice Cream You wish to estimate, with 95% confidence, the population proportion of U.S. adults who say that chocolate is their favorite ice cream flavor. a. No preliminary estimate is available, in other words, a pilot sample is not available. Find the minimum sample size needed. b. Find the minimum sample size needed, using a prior study that found that 28% of U.S. adults say that chocolate is their favorite ice cream flavor. c. Compare the results from parts (a) and (b). d. Verify the result from part (b) with PHS5tat