Question

Find each of the following probabilities for a normaldistribution.a. p(-1.80 < z < 0.20)b. p(-0.40 < z < 1.40)c. p(0.25 < z < 1.25)d. p(-0.90 < z < -0.60)

Answer 1

Answer:

a. 0.5434

b. 0.5746

c. 0.2957

d. 0.0902

Step-by-step explanation:

To find each probability we need to use the normal distribution table that is accumulated to the left, so each probability is equal to

P(-1.80 < z < 0.20) = P( z < 0.20) - P( z < -1.80)

P(-1.80 < z < 0.20) = 0.5793 - 0.0359

P(-1.80 < z < 0.20) = 0.5434

P(-0.40 < z < 1.40) = P( z < 1.40) - P( z < -0.40)

P(-0.40 < z < 1.40) = 0.9192 - 0.3446

P(-0.40 < z < 1.40) = 0.5746

P(0.25 < z < 1.25) = P(z < 1.25) - P(z < 0.25)

P(0.25 < z < 1.25) = 0.8944 - 0.5987

P(0.25 < z < 1.25) = 0.2957

P(-0.90 < z < -0.60) = P(z < -0.60) - P(z < -0.90)

P(-0.90 < z < -0.60) = 0.2743 - 0.1841

P(-0.90 < z < -0.60) = 0.0902

Therefore, the answers are

a. 0.5434

b. 0.5746

c. 0.2957

d. 0.0902