X is a normally distributed random variable with a mean of 22 and a standard deviation of 5. The probability that X is less than 9.7 is
A)0.000
B)0.4931
C)0.0069
D)0.9931

Question

Quizplus · Accepted Answer

We need to find the cumulative probability of X being less than 9.7.

Z-score = (9.7 - 22) / 5 = -2.46

Using a standard normal distribution table or calculator, we find that the cumulative probability of Z being less than -2.46 is 0.0069.

Therefore, the probability that X is less than 9.7 is also 0.0069.

X Is a Normally Distributed Random Variable with a Mean