Question

use standard normal table to find the z- score that corresponds to the cumulative area 0.7157 if the area is not in the table use the entry closet to the area is halfway between two entries use the z-score halfway between the corresponding z-scores

Answer 1

ANSWER:-

P(-z < Z < z) = 0.7157
P(Z < z) - P(Z < z) = 0.7157
2P(Z < z) - 1 = 0.7157
2P(Z < z) = 1 + 0.7157
2P(Z < z) = 1.7157
P(Z < z) = 1.7157  / 2
P(Z < z) = 0.85785  

P(Z < z) = 0.85785       Using z table,

P(Z < 1.071) = 0.85785   
z = 1.071