Question

The distribution of a sample of the outside diameters of PVC gas pipes approximates a symmetrical, bell-shaped distribution. The arithmetic mean is 14.0 inches, and the standard deviation is 0.1 inches. About 68 percent of the outside diameters lie between what two amounts? please show detailed work

A. 13.5 and 14.5 inches

B. 13.0 and 15.0 inches

C. 13.9 and 14.1 inches

D. 13.8 and 14.2 inches

Answer 1

Given,

= 14 , = 0.1

According t empirical (68 - 95 - 99.7) rule,

Approximately, 68% of the data falls in 1 standard deviation of the mean.

That is 68% of the data falls in - 1 * and   + 1 *

= 14 - 1* 0.1 and 14 + 1 * 0.1

= 13.9 and 14.1 inches