This is a question about Statistical Process Control.

Pairs of Yeezy sneakers are supposed to weigh exactly 1kg. Inspectors want to develop process control charts. They take ten samples of six pairs each and weigh them.

Question: Based on the following data (in kg), compute the lower and upper control limits and determine whether the process is in control. (Note that the overall standard deviation of the population is unknown.)

Sample	Mean	Range
1 2 3 4 5 6 7 8 9 10	1.20 .90 .80 1.10 1.00 1.30 1.10 .95 1.20 1.45	.2 .2 .3 .4 .1 .6 .6 .2 .3 .4