Refer to the table Factors for Computing Control Chart Limits $(3$ sigma$)$LOADING$...$ for this problem.

Autopitch devices are made for both$$ major$-$ and$$ minor$-$league teams to help them improve their batting averages. When set at the standard$$ position, Autopitch can throw hardballs toward a batter at an average speed of $65$ mph$.$ To monitor these devices and to maintain the highest$$ quality, Autopitch executive Neil Geismar takes samples of $9$ devices at a time. The average range is $5$ mph$.$

Part $2$

$$a$)$ Using this$$ information, construct control limits for the x overbar$-$chart.