Posted by **Clay** on Tuesday, November 27, 2012 at 1:45am.

A simple random sample of 50 female 14-year-olds is selected. The sample mean height of the girls is found to be 62 inches. Assume the height of 14-year-old girls is normally distributed with a standard deviation of 5 inches.

1. Based on these data, a 95% confidence interval for the true mean height of all

14-year-old girls is:

A) 62 +/- 1.96

B) 62 +/- 1.386

C) 62 +/- 1.645

D) 62 +/- 0.196

2. Which of the following correctly interprets the 95% confidence interval for the true

mean height of all 14-year-old girls?

A) We can be 95% confident that the sample mean height of 14-year-old girls is within

the confidence interval obtained.

B) If this study were to be repeated with a sample of the same size, there is a 0.95

probability that the sample mean height of 14-year-old girls would be in the interval

obtained.

C) We can be 95% confident that the population mean height of all 14-year-old girls is

within the interval obtained.

D) 95% of all 14-year-old girls have heights within the interval obtained.