1. A quality analyst wants to construct a sample mean and range charts for controlling a packaging process. He knows from past experience that when the process is op- erating as intended, packaging weight is normally distributed with a mean of twenty ounces, and a process standard devia- tion of two ounces. Each day last week, he randomly selected 2. Pairs of Yeezy sneakers are supposed to weigh exactly four packages and weighed each. The data he collected ap- pear below in ounces. (b) With a value of z that would provide 99.73% confidence, construct an Xbar and R charts for this process. what do you conclude about the process – is it in control? Answer: Ikg. Inspectors want to develop process control charts. They take ten samples of six pairs each and weigh them. 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 un- Day Package l Package ? Package 3 Package 4 Monday 23 22 23 24 Tuenday 23 21 19 21 Wednesday 20 19 20 21 Thunday 18 19 20 19 known. Friday 18 20 22 20

When we calculate intervals in probability and statistics, it can be simply termed as finding out a confidence interval. The confidence interval is usually calculated from the data set which is observed. The value of the parameter that needs to be calcul…