A random sample of 400 Canadian grocery shoppers reveals that 26% of them are trying to make healthier food choices.
a. Construct a 90% confidence interval estimate of the proportion of all Canadian grocery shoppers who are trying to make healthier food choices.
b. Construct a 96% confidence interval estimate of the proportion of all Canadian grocery shoppers who are trying to make healthier food choices.
c. Construct a 99% confidence interval estimate of the proportion of all Canadian grocery shoppers who are trying to make healthier food choices.
d. Compare the three intervals you created for parts a, b, and c of this question. What hap pens to the width of the confidence interval as the desired level of confidence increases?