1) A manufacturer of headphones is interested in the sales of a particular headphone model in its stores in 8 airports.

SD

42.89

44.71

7.14

To get full points when answering each part below be sure to: calculate an appropriate statistic, state the result of the test, and state your conclusion.

a)    Looking at all the stores, is there a difference in sales between January and March? [6 points]

b)    Did the campaign have a different effect on sales for stores on the East coast versus on the West coast? [6 points]

c)    Was there a difference in sales in January for stores on the East coast versus on the West coast? [6 points]