Consumers can purchase nonprescription medications at food s

Consumers can purchase nonprescription medications at food stores, mass merchandise stores such as Kmart and Wal-Mart, or pharmacies. About 45% of consumers make such purchases at pharmacies. What accounts for the popularity of pharmacies, which often charge higher prices? A study examined consumers\' perceptions of overall performance of the three types of stores, using a long questionnaire that asked about such things as \"neat and attractive store,\" \"knowledgeable staff,\" and \"assistance in choosing among various types of nonprescription medication.\" A performance score was based on 27 such questions. The subjects were 218 people chosen at random from the Indianapolis telephone directory. Here are the means and standard deviations of the performance scores for the sample.

We do not know the population standard deviations, but a sample standard deviation s from so large a sample is usually close to ?. Use s in place of the unknown ? in this exercise.

(a) What population do you think the authors of the study want to draw conclusions about?

consumersthe American public    sick peoplecitizens of Indianapolispharmacies

What population are you certain they can draw conclusions about?

the American publicpharmacies    consumerssick peoplecitizens of Indianapolis

(b) Give 90% confidence intervals for the mean performance for each type of store.

Solution

) Suppose that p = 0.49 is exactly true for
the population of all stores. a sample standard deviation s from so large a sample is usually close to ?
SRS of size n = 1006 falls between 0.46 and 0.52;

b)for a 95% confidence interval, we go to the row identified by 95.000 in the first column and extract an interval of (9.25824, 9.26468)\', So the Upper limit for food store in 2 digits =9.26

c)As above, the lower mass mechandizers = 9.25

d)Upper confidence 0.95

e) 0.91 for pharma

f) 0,298 to inf.