Chapter 4.3, Problem 13E

The Truly Amazing Dudes are a group of comic acrobats. The heights (in inches) of the ten acrobats are as follows:

$68$ $50$ $70$ $67$ $72$ $78$ $69$ $68$ $66$ $67$

Is your height or weight “average”? The characteristics can vary considerably within any specific group of people. The mean is used to represent the average, and the standard deviation is used to measure the “spread” of a collection of data.

a. Find the mean and standard deviation of the heights.

b. What percent of the data lies within one standard deviation of the mean?

c. What percent of the data lies within two standard deviation of the mean?