Answer:
The mean and SD will change
The median is a better measure of the center since it will not change in this case
Step-by-step explanation:
Given that the value 100 was changed to 15, what will happen is that the value of the mean will decrease since there is a lower total value now. This will consequently decrease the value of the standard deviation too.
Yes, the median will be a better choice
This is because, by changing the value of 100 to 15, the value of the median stays the same and thus the previous information would not be changed if the median we used .