2. Random samples of four brands of cigarettes were tested for a tar content. The following figures show the milligrams of tar found in the 16 cigarettes tested:

Brand A

14 10 11 13

Brand B

16 18 14 15

Brand C

16 15 14 12

Brand D

17 20 19 21

Use the 0.05 level of significance to test whether there is a significant difference in tar content among the four brands of cigarettes.

2. Random samples of four brands of cigarettes were tested for a tar content. The following figures show the milligrams of tar found in the 16 cigarettes tested: Brand A Brand B Brand C Brand D 14 16 16 17 10 18 15 20 11 14 14 19 13 15 12 21 Use the 0.05 level of significance to test whether there is a significant difference in tar content among the four brands of cigarettes