Over the next 30 days, economists forecast that the pound may weaken relative to the dollar by as much as 7% or strengthen by as much as 6%.
Assume for simplicity that the possible outcomes for the rate of change in the GBPUSD spot rate are:
-7, -5,-3,-1, 0, 2, 5, and 6 percent
If these possibilities are equally likely, what are the mean and standard deviation of the future spot rate if the current rate is 1.312 dollars per pound?