Question

Find the area under the standard normal curve between z = −2.57 and z = 1.27. Round your answer to four decimal places, if necessary.

Answer 1

P(-2.57 ≤ Z ≤ 1.27) = P(Z ≤ 1.27) - P(Z ≤ -2.57)

P(Z ≤ 1.27) = 0.8980
P(Z ≤ -2.57) = 1 - P(Z ≤ 2.57) = 1 - 0.99488 = 0.00512

P(-2.57 ≤ Z ≤ 1.27) = 0.8980 - 0.00512 = 0.89288
0.8929 (4 d.p.)