A researcher wishes toestimate, with 95% confidence, the population proportion of adults who say chocolate is their favorite ice cream flavor. Her estimate must be accurate within 5% of the population proportion.

(a) No preliminary estimate is available. Find the minimum sample size needed.

(b) Find the minimum sample sizeneeded, using a prior study that found that 22% of the respondents said their favorite flavor of ice cream is chocolate.

(c) Compare the results from parts(a) and(b).