The owner of a fish market has an assistant who has determined that the weights of catfish are normally distributed,with mean of 3.2 pounds and standard deviation of 0.8 pound.If a sample of 64 fish yields a mean of 3.4 pounds,what is probability of obtaining a sample mean this large or larger?
A)0.0001
B)0.0013
C)0.0228
D)0.4987

Question

Quizplus · Accepted Answer

We first need to calculate the standard error of the mean:

SE = σ/√n = 0.8/√64 = 0.1

Next, we calculate the z-score:

z = (x̄ - μ) / SE = (3.4 - 3.2) / 0.1 = 2

Using a standard normal distribution table, the probability of obtaining a z-score of 2 or larger is 0.0228. Therefore, the answer is (C).

The Owner of a Fish Market Has an Assistant Who