A Company That Manufactures Health Food Snacks Produces Low Sodium

A company that manufactures health food snacks produces low sodium rice chips.To monitor the process for sodium levels, chips are selected periodically and the amount of sodium (mg) measured.For each of thirty samples consisting of 8 chips, the mean and range in sodium content is determined.The average of the means across all samples is 55 mg and the average range is 2.2 mg.The lower and upper control limits for the R chart are ________________________ .

A) 0.2992 and 4.1008 mg.
B) 0 and 4.4088 mg.
C) 0.136 and 1.864 mg.
D) 2.1999 and 30.152 mg.
E) 0.2493 and 3.4167 mg.