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 cm, and the standard deviation is 0.1 cm. About
68 percent of the outside diameters lie between what two amounts?
A) 13.5 and 14.5 cm
B) 13.0 and 15.0 cm
C) 13.9 and 14.1 cm
D) 13.8 and 14.2 cm
E) None of the choices are correct.

Question

Quizplus · Accepted Answer

In a normal distribution, about 68% of the data falls within one standard deviation of the mean. Therefore, the range is 14.0 cm ± 0.1 cm, which is 13.9 cm to 14.1 cm.

The Distribution of a Sample of the Outside Diameters of PVC