Question

You may need to use the appropriate appendix table to answer this question.

Given that z is a standard normal random variable, compute the following probabilities. (Round your answers to four decimal places.)

(a)

P(−1.96 ≤ z ≤ 0.49)

(b)

P(0.52 ≤ z ≤ 1.24)

(c)

P(−1.75 ≤ z ≤ −1.02)

Pls explain how you did it

Answer 1

Solution :

Using standard normal table,

(a)

P(-1.96 z 0.49) = P(z 0.49) - P(z -1.96) = 0.6879 - 0.025 = 0.6629

(b)

P(0.52 z 1.24) = P(z 1.24) - P(z 0.52) = 0.8925 - 0.6985 = 0.1940

(c)

P(-1.75 z -1.02) = P(z -1.02) - P(z -1.75) = 0.1539 - 0.0401 = 0.1138