Using sample statistics and the data from Problem 3.12, construct a 95% confidence interval:

(a) for a single observation, and identify any observations that may be identified as possible outliers in the data.

(b) for the mean.

Problem 3.12

Problem 3.12

Using the following data set, answer the questions that follow.

17.5 15.0 13.4 23.9 25.2 19.5 25.8 30.0 22.5 35.3 39.5 23.5 26.5 21.3 22.3 21.6 27.2 21.1 24.0 23.5 32.5 32.2 24.2 35.7 28.0 24.0 16.8 21.1 19.0 30.7 30.2 33.7 19.7 19.7 25.1 27.9 28.5 22.7 31.0 28.4 31.2 24.6 30.2 16.8 26.9 23.3 21.5 18.8 21.4 20.7

(a) What are the mean and standard deviation of the data set?

(b) Construct a centered relative frequency histogram of the data using seven intervals and discuss whether it appears to be a normal data set.

(c) What is the E95 interval for this data set?

(d) Would there be any reason to question the validity of any observation at the 95% level?