Question

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. 0.0069
b. 0.000
c. 0.4931
d. 0.9931

Answer 1

0.0069

Explanation:

According to the Question,

• Given That, 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

We have, μ=22 , σ= 5 , P(X<9.7)=Area to the left of 9.7.

Z = (x-μ)/σ

Z = (9.7-22) / 5 ⇒ -2.46

Thus,

• P(X<9.7)=P(Z < -2.46) ⇒ 0.0069 (From z-table)