This question is incomplete, the complete question is;
Given that is a standard normal random variable, find for each situation (to 2 or 3 decimals)
a. The area to the left of z is 0.8
b. The area to the left of z is 0.882
c. The area to the right of z is 0.8225
(Hint: Enter the positive z-value)
Answer:
a) z = 0.84
b) z = 1.185
c) z = -0.925
Explanation:
a)
area to the left of z is 0.8
Making use of the standard normal table
p( Z < z ) = 0.8
we check the the probability of 0.8 in the standard normal table
so the corresponding value of z is 0.84
p( Z < 0.84 ) = 0.8
z = 0.84
b)
area to the left of z is 0.882
Making use of the standard normal table
p( Z < z ) = 0.882
we check the the probability of 0.882 in the standard normal table
so the corresponding value of z is 1.185
p( Z < 1.185 ) = 0.882
z = 1.185
c)
area to the right of z is 0.8225
Making use of the standard normal table
p( Z > z ) = 0.8225
1 - p( Z < z ) = 0.8225
p( Z < z ) = 1 - 0.8225
p( Z < z ) = 0.1775
p( Z < -0.925 ) = 0.1775
z = -0.925