Go to www.pearsonhighered.com/sullivanstats to obtain the data file 9_2_37 using the file format of your choice for the version of the text you are using. The data represent the width (in yards) and length (in miles) of a random sample of tornadoes that struck Oklahoma. The variable "length" represents the number of miles a particular tornado was on the ground.

(a) Draw a relative frequency histogram of the variable length using a lower class limit of the first class of 0 and a class width of 3. Comment on the shape of the distribution.

(b) Draw a boxplot of the length. Are there any outliers?

(c) Explain why a large sample is necessary to construct a confidence interval for the mean length of a tornado in Oklahoma.

(d) Use statistical software to construct and interpret a 95% confidence interval for the mean length of a tornado in Oklahoma?