How Big Is the Difference, Really?

Compare the gap between the means with the spread within each group.

ExampleTeam A has a mean of 70 cm and a mean absolute deviation of 2 cm. Team B has a mean of 76 cm and the same mean absolute deviation. How many mean absolute deviations apart are the two means, and how clearly do the groups differ? The means differ by 76 − 70 = 6 cm. That is 6 ÷ 2 = 3 mean absolute deviations. A gap of 3 MADs is large compared with the spread, so the two groups really do differ.

1.Team A has a mean of 61 cm and a mean absolute deviation of 2 cm. Team B has a mean of 69 cm and the same mean absolute deviation. How many mean absolute deviations apart are the two means, and how clearly do the groups differ?
2.The morning group has a mean of 47 ms and a mean absolute deviation of 3 ms. The afternoon group has a mean of 53 ms and the same mean absolute deviation. How many mean absolute deviations apart are the two means, and how clearly do the groups differ?
3.Class 7A has a mean of 42 points and a mean absolute deviation of 4 points. Class 7B has a mean of 58 points and the same mean absolute deviation. How many mean absolute deviations apart are the two means, and how clearly do the groups differ?
4.The morning group has a mean of 49 ms and a mean absolute deviation of 2 ms. The afternoon group has a mean of 55 ms and the same mean absolute deviation. How many mean absolute deviations apart are the two means, and how clearly do the groups differ?
5.The morning group has a mean of 63 ms and a mean absolute deviation of 2 ms. The afternoon group has a mean of 71 ms and the same mean absolute deviation. How many mean absolute deviations apart are the two means, and how clearly do the groups differ?