4. A supermarket chain manager wants to know if its "buy one, get one free" campaign increases customer traffic enough to justify the cost of the program. For each of the 10 stores, it selects two days at random to run the test. For one of those days, the program will be in effect. Here are the results in the number of customer visits to the 10 stores.

Test the manager's hypothesis using a level of significance of = 10%.

Show all significant steps and state any necessary assumptions.

Store # With Program Without Program

1 140 136

2 233 235

3 110 108

4 42 35

5 332 328

6 135 135

7 151 144

8 33 39

9 178 170

10 147 141