The probability is .80 that a standard normal random variable is between -z and +z. The value of z is approximately:
A)1.28.
B)1.35.
C)1.96.
D)1.45.

Question

Quizplus · Accepted Answer

The value of z that corresponds to a probability of .80 (or 80%) in a standard normal distribution is approximately 1.28. This is because the area under the standard normal curve between -z and +z for 80% of the distribution is captured by z scores of approximately ±1.28.

The Probability Is