Nurses wondered if birth weights of babies are going up They

Nurses wondered if birth weights of babies are going up. They knew that the average birth weight of a baby last year was 7.6 pounds. A random sample of 15 weights of babies at the hospital where the nurses work gave an average birth weight of 7.9 pounds. Nurses felt that the birth weights this year were normally distributed. Which of the following is true about the distribution of sample means?

Choose the correct answer below.

A.

Since the sample size is less than 30, the population data cannot be normally distributed. Therefore, the distribution of sample means will not be normally distributed.

B.

The distribution of sample means will be normal regardless of the shape of the data in the population.

C.

The distribution of sample means will not be normal even though the population data followed a normal distribution because the sample size is less than 30.

D.

Even though the sample size is less than 30, the distribution of sample means will be normal because the population data follow a normal distribution.

Solution