A survey reported that in a recent year, the mean serum cholesterol level in milligrams per deciliter for U.S. adults was 203 with a standard deviation of 39. A random sample of 102 adults was Chosen. What is the probability that the mean cholesterol level is between 199 and 208?
A) 0.7523
B) 0.2477
C) 0.9015
D) 1.2900

Question

Quizplus · Accepted Answer

The probability that the mean cholesterol level is between 199 and 208 can be found using the standard normal distribution (Z-score) and the central limit theorem. Given the mean (μ) = 203, standard deviation (σ) = 39, and sample size (n) = 102, we first find the standard error (SE) = σ / sqrt(n) = 39 / sqrt(102). Then, we calculate the Z-scores for 199 and 208, and use the Z-table to find the probabilities. The calculations yield a probability of 0.7523, making option A correct.

A Survey Reported That in a Recent Year, the Mean