Retailers at the local shopping mall want to survey their Saturday customers about their satisfaction with the eating facilities within the mall. One merchant went to business school and learned about the importance of statistics, so he wants to obtain a random sample. He proposes the following method:Interviewers should stand at the center of the mall and select the first 100 people who walk by after 11:00 a.m. He believes this approach will provide a random sample because the interviewers will not exercise any decision over whether or not to include specific individuals in the sample.

a. What kind of sample would the merchant really get?

b. In what way might this sampling method be biased?

c. Describe how the merchant could modify this approach to use a version of systematic sampling.

d. If the retailer were to use stratified random sampling, what strata would you recommend that he choose?

e. How would you improve the merchant's sampling procedure?