Discussion:
How to make x bar chart and R chart
Q: A bank manager decides to study waiting times of customers for teller service at the noon lunch hour (noon to 1pm). He observes three customers to measure the time the customer enters the line to the time he or she reaches the teller window. He records this over several days.
Time in Minutes
Day Customer #1 Customer #2 Customer #3
1 7.2 8.4 7.9
2 5.6 8.7 3.3
3 5.5 7.3 3.2
4 4.4 8.0 5.4
5 9.7 4.6 4.8
6 8.3 8.9 9.1
Please draw the X-bar Chart and R-chart.