Question

1 point) A market research firm supplies manufacturers with estimates of the retail sales of their products from samples of retail stores. Marketing managers are prone to look at the estimate and ignore sampling error. An SRS of 14 stores this year shows mean sales of 69 units of a small appliance, with a standard deviation of 8.6 units. During the same point in time last year, an SRS of 19 stores had mean sales of 58.938 units, with standard deviation 16.3 units. An increase from 58.938 to 69 is a rise of about 15%.

1. Construct a 99% confidence interval estimate of the difference μ1−μ2, where μ1 is the mean of this year's sales and μ2 is the mean of last year's sales.

(a) _________<(μ1−μ2)< _________

(b) The margin of error is _______

2. At a 0.01 significance level, is there sufficient evidence to show that sales this year are different from last year?

A. Yes

B. No

Answer 1

No, there is insufficient evidence to show that sales this year are different from last year