Use the table. Which inference can you make by comparing the measures of center?

Finish Times of 30 Runners

in the 100-meter Dash

Mean MAD

Last Year 16.2 s 1.2

This Year 14.7 s 1.9

Answer: the average speed of the runners increased since last year.

Step-by-step explanation:

The table is:

Mean MAD

Last Year 16.2 s 1.2

This Year 14.7 s 1.9

Looking at this table we can see that this year, the mean time is smaller than the one from last year, so the runners are faster in average.

The mean absolute deviation is bigger, but the change in the mean is bigger.

difference of the mean 16.2 - 14.7 = 1.5

difference of the MAD 1.9 - 1.2 = 0.7

This means that the average speed of the runners increased since last year, and the fact that the MAD increased means that not all the runners increased their speed at the same rate, so now the speeds of the different runners are not as alike like last year.