Question 1149161
(a)  Probability (P) (X > 80) = 1 - P(X < 80)
:
z-score(80) = (80 - 70)/10 = 1
:
Lookup a z-score of 1 in the table of z-values and its associated P
:
P(X < 80) = 0.8413
:
P(X > 80) = 1 - 0.8413 = 0.1587
:
(b)  z-score(60) = (60 -70)/10 = -1
:
P(X < 60) = 0.1587
:
P(X > 60) = 1 - 0.1587 = 0.8413
: