Given a normal distribution with a mean of 80 and a standard deviation of 20, an observation of x = 50 corresponds to a standard normal deviate:
A) of z = +1.5
B) of z = +3.0
C) of z = -1.5
D) of z = -3.0
E) of none of these

Question

Quizplus · Accepted Answer

To find the standard normal deviate, we use the formula z = (x - μ) / σ, where x is the observation, μ is the mean, and σ is the standard deviation. Plugging in the values, we get z = (50 - 80) / 20 = -1.5. Therefore, the answer is choice C.

Given a Normal Distribution with a Mean of 80 and a Standard