If the random variable Z has a standard normal distribution, then P(1.25 ≤ Z ≤ 2.17) is:
A)0.0906.
B)0.9200.
C)0.4700.
D)0.3944.

Question

Quizplus · Accepted Answer

This probability can be found using standard normal distribution tables or a calculator with statistical functions. The probability that Z is between 1.25 and 2.17 is the difference between the cumulative probability up to 2.17 and the cumulative probability up to 1.25. According to standard normal distribution tables, P(Z ≤ 2.17) ≈ 0.9850 and P(Z ≤ 1.25) ≈ 0.8944. Therefore, P(1.25 ≤ Z ≤ 2.17) = 0.9850 - 0.8944 = 0.0906.

If the Random Variable Z Has a Standard Normal Distribution