Question 1103157
z=(x-mean)/sd
a.  (3.8-3.1)/0.7=1
P(z>1)=0.1587
b.(2-3.1)/0.7=-1.1/0.7=-1.57
(2.6-3.1)/0.7=-0.5/0.7=-0.71
P(z between -0.71 and -1.57)=0.1806 (corrected)