• • S6.30 Autopitch devices are made for both major- and minor-league teams to help them improve their batting averages.

When set at the standard position, Autopitch can throw hardballs toward a batter at an average speed of 60 mph. To monitor these devices and to maintain the highest quality, Autopitch executive Neil Geismar takes samples of 10 devices at a time. The average range is 3 mph. Using this information, construct control limits for:

a) x chart.

b) R chart