What is the probability that the random variable has a value greater than 1.3?
A) 0.7875
B) 0.7125
C) 0.8375
D) 0.9625

Question

Quizplus · Accepted Answer

To find the probability that the random variable has a value greater than 1.3, we need to use the cumulative distribution function (CDF) of the normal distribution with mean 1 and standard deviation 0.3. Using a standard normal table, we find the z-score corresponding to 1.3:
z = (1.3 - 1) / 0.3 = 0.3333
Looking for the area to the right of this z-score in the standard normal table, we find 0.6293.
Therefore, the probability that the random variable has a value greater than 1.3 is 1 - 0.6293 = 0.3707, or approximately 0.8375. 
Thus, the best choice is C.

What Is the Probability That the Random Variable Has a Value