Birth weights at a local hospital have a Normal distribution, with a mean of 110 oz and a standard deviation of 15 oz. The proportion of infants with birth weights above 125 oz is:
A)0.500.
B)0.159.
C)0.341.
D)0.841.

Question

Quizplus · Accepted Answer

To find the proportion of infants with birth weights above 125 oz, we need to standardize the value using z-score formula:

z = (x - μ) / σ

where x = 125, μ = 110, and σ = 15

z = (125 - 110) / 15 = 1

Using a standard Normal distribution table, we can find the proportion of values above z = 1, which is approximately 0.159. Therefore, the answer is B.

Birth Weights at a Local Hospital Have a Normal Distribution