There are a lot of questions and work here, I can help you get started in the right direction.
On the left, you have the heights for Soil A. On the right, you have the height for Soil B. Looking at the overlap, there are a lot of heights in the 60's and 70's for both.
To calculate the mean, add up all the values and divide by the total.
For the MAD, you have to subtract each value from the mean. Then, take the absolute value of it. Finally, find the mean of those values.
The one with the higher MAD is more variable.
