It is known that the body mass index (BMI) of healthy American males follows a normal distribution, with a mean of 24.5 and a standard deviation of 3.0.Approximately what proportion of male BMI values fall below 18.5?
A) 0.0003
B) 0.025
C) 0.05
D) 0.16

Question

Quizplus · Accepted Answer

To find the proportion of male BMI values below 18.5, we use the Z-score formula: Z = (X - μ) / σ, where X is the value of interest (18.5), μ is the mean (24.5), and σ is the standard deviation (3.0). Plugging in the values, we get Z = (18.5 - 24.5) / 3 = -6 / 3 = -2. A Z-score of -2 corresponds to approximately 2.5% of the distribution lying below this value, based on standard normal distribution tables.

It Is Known That the Body Mass Index (BMI) of Healthy