The annual income of residents in a certain county is normally distributed, with a mean of $42,000 and a standard deviation of $10,000. What is the probability that a randomly chosen resident has income over $52,000?
A) 16%
B) 32%
C) 50%
D) 68%

Question

Quizplus · Accepted Answer

To find the probability of a resident earning over $52,000, we calculate the Z-score: Z = (X - μ) / σ = (52,000 - 42,000) / 10,000 = 1. A Z-score of 1 corresponds to the top 16% of the normal distribution, hence the probability is 16%.

The Annual Income of Residents in a Certain County Is