Question 978629
z=(score-mean)/sd

a) z= 12/5.8 or 2.07.  Prob z>2.07=0.019

b.This is the probability of a z score of -1.724 and 2.586,  -10/5.8 and 15/5.8
It should be very large.  It is 0.9519

c. z must be less than -5/5.8 ;; z<-0.8621;; probability is 0.1943