consider the graphs which summarize the data on the number of hours per night on average of sleep by two groups: 5th grade boys and 10th grade boys.
choose all that are correct.
the mean hours for the 5th grade boys is 8.6.
the mean hours for the 10th grade boys is 7.9.
the mean absolute deviation (mad) for the 5th grade boys is 0.50.
the mean absolute deviation (mad) for the 10th grade boys is 0.40.
there is a meaningful difference in the number of hours of sleep between the groups because the difference between the two means is greater than 2 mads.