A supermarket chain wants to know if their buy one, get one free campaign increases customer traffic

A supermarket chain wants to know if their €œbuy one, get one free€ campaign increases customer traffic enough to justify the cost of the program. For each of 10 stores they select two days at random to run the test. For one of those days (selected by a coin flip), the program will be in effect. They want to test the hypothesis that there is no mean difference in traffic against the alternative that the program increases the mean traffic. Here are the results in number of customer visits to the 10 stores:

a) Are the data paired? Explain.
b) Compute the mean difference.
c) Compute the standard deviation of the differences.
d) Compute the standard error of the mean difference.
e) Find the value of the t-statistic.
f) How many degrees of freedom does the t-statistic have?
g) Is the alternative one- or two-sided? Explain.
h) What is the P-value associated with this t-statistic?
(Assume that the other assumptions and conditions for inference are met.)
i) At α = 0.05, what do you conclude?

Transcribed Image Text:

With Program 140 233 110 42 332 135 151 Without Program 136 235 108 35 328 135 144 39 170 141 Store # 178 10 147