The monthly growth of the height of trees in Montana has a mean of 47.5" and a standard deviation of 11.6". Assume a normal probability distribution.
a) The monthly growth amount for any future month that has a 50 percent chance of being equaled or exceeded.
b) The monthly amount that has a 20 percent chance of being equaled or exceeded.
c) The probability that the growth in any month will be between 38 and 62 inches.