10.65
The data below represent the lifetime of four different alloys.
Alloy
1 | 2 | 3 | 4 |
999 | 1022 | 1026 | 974 |
1010 | 973 | 1008 | 1015 |
995 | 1023 | 1005 | 1009 |
998 | 1023 | 1007 | 1011 |
1001 | 996 | 981 | 995 |
- At the 0.05 level of significance, is there evidence of a difference in the mean lifetime of the four alloys?
- If appropriate, determine which alloys differ in mean lifetime.
- At the 0.05 level of significance, is there evidence of a difference in the variation in lifetime among the four alloys?
- What effect does your result in (c) have on the validity of the results in (a) and (b
10.67
The retailing manager of a supermarket chain wants to determine whether product location has any effect on the sale of pet toys. Three different aisle locations are considered: front, middle, and rear. A random sample of 18 stores is selected wit 6 stores randomly assigned to each aisle location. The size of the display area and price of the product are constant for all stores. At the end of a 1-month trial period, the sales volumes (in thousands of dollars) of the product in each store were as follows:
FRONT | MIDDLE | REAR |
8.6 | 3.2 | 4.6 |
7.2 | 2.4 | 6.0 |
5.4 | 2.0 | 4.0 |
6.2 | 1.4 | 2.8 |
5.0 | 1.8 | 2.2 |
4.0 | 1.6 | 2.8 |
At the 0.05 level of significance, is there evidence of a significant difference in mean sales among the various aisle locations?
- If appropriate, which aisle locations appear to differ significantly in mean sales?
- At the 0.05 level of significance, is there evidence of a significant difference in the variation in sales among the various aisle locations?
- What should the retailing manager conclude? Fully describe the retailing manager’s options wit respect to aisle locations.