A medical clinic asks all of its patients to complete a quick survey after each appointment. Patients are asked to rate their experience on a scale of 1 to 10, with 1 representing a very poor experience, and 10 representing an excellent experience. The surveys are separated into categories based on age. Then, each month, a random sample of 10 surveys are gathered from each age category. The results of this month's random samples of the 40-60 age group and the 60+ age group are shown below.

40 - 60 2 6 5 5 3 7 3 9 1 4
60+ 4 8 7 10 3 6 5 8 9 5
The mean rating of the 40-60 group is two points than the mean rating of the 60+ group. This difference is about the variability of either group.