You will have complete sales information for last month in a week, but right now you have data from a random sample of 40 stores. The meanchange in sales in the sample is −3.2%, and the standard deviation of the changes is

12%. Are average sales for all stores different from last month?

(a) State appropriate null and alternative hypotheses. Explain how you decided between the one- and two-sided alternatives.

(b) Find the t statistic and its P-value. State your conclusion using the α = 0.05 significance level.

(c) If the test gives strong evidence against the null hypothesis, would you conclude that monthly sales are different in every one of your stores? Explain your answer


"Looking for a Similar Assignment? Get Expert Help at an Amazing Discount!"
Looking for a Similar Assignment? Our Experts can help. Use the coupon code SAVE30 to get your first order at 30% off!