Flight delays are of concern to passengers. An airline obtained observations on the average and range of delay times of flights (in minutes), each chosen from a sample of size 4, as shown in Table 7-20.
Construct appropriate control charts and comment on the performance level. What are the chances of meeting a goal of no more than a 10-minute delay?
![2107_Table.jpg](https://secure.tutorsglobe.com/CMSImages/2107_Table.jpg)