The correct answer for the question that is being presented above is this one:
To find the mean of a set, add up all of the numbers and divide by how many numbers you have. For the first set:
u = (10.7+2.4)/2 = 6.55
For the second set:
u = (13.7 + 2.5)/2 = 8.1
To find the mean absolute deviation, (MAD) find the mean of the distances of each number from the mean.
First set:
MAD = (|10.7-6.55| + |2.4-6.55|)/2 = 4.15
Second set:
MAD = (|13.7-8.1| + |2.5-8.1|)/2 = 5.6
The means-to-MAD ratio is simply that, divide one by the other and that's it.
For the first set:
6.55 / 4.15 = 1.57831325
For the second set:
8.1 / 5.6 = 1.44642857