question archive A cereal company wants to see which of two promotional strategies, supplying coupons in a local newspaper or including coupons in the cereal package itself, is more effective
A cereal company wants to see which of two promotional strategies, supplying coupons in a local newspaper or including coupons in the cereal package itself, is more effective
Subject:StatisticsPrice: Bought3
A cereal company wants to see which of two promotional strategies, supplying coupons in a local newspaper or including coupons in the cereal package itself, is more effective. (In the latter case, there is a label on the package indicating the presence of the coupon inside.) The company randomly chooses 80 Kroger's stores around the country—all of approximately the same size and overall sales volume—and promotes its cereal one way at 40 of these sites, and the other way at the other 40 sites. (All are at different geographical locations, so local newspaper ads for one of the sites should not affect sales at any other site.) Unfortunately, as in many business experiments, there is a factor beyond the company's control, namely, whether its main competitor at any particular site happens to be running a promotion of its own. The file P09_70.xlsx has 80 observations on three variables:
-Sales: number of boxes sold during the first week of the company's promotion
-Promotion Type:1 if coupons are in local paper, 0 if coupons are inside box
-Competitor Promotion:1 if main competitor is running a promotion, 0 otherwisea. Based on all 80 observations,
(1) Calculate the difference in sample mean sales (promotion type 0 minus promotion type 1) between stores running the two different promotional types. Round your answer to one decimal place, if necessary.
(2) Calculate the standard error of this difference. Round your answer to two decimal places, if necessary.
(3) Calculate the 90% confidence interval for the population mean difference. Round your answer to one decimal place, if necessary. If your answer is negative number, enter "minus" sign.
Lower Limit___________________
Upper Limit___________________
b. Test whether the population mean difference is zero (the null hypothesis) versus a two-tailed alternative. State whether you should reject or fail to reject the null hypothesis.
Select
Reject
Do not reject
Item 6
the null hypothesis. The confidence interval Select
does not support
supports
Item 7
this claim because it Select
does not include
includes
Item 8
.
c. Test whether the population mean difference is zero (the null hypothesis) versus a two-tailed alternative, but now restrict the population to stores where the competitor is not running a promotion of its own. State whether you should fail to reject or reject the null hypothesis.
Select
Reject
Do not reject
Item 10
the null hypothesis. The confidence interval Select
does not support
supports
Item 11
this claim because it Select
does not include
includes
Item 12
