You run a blood testing lab at a large urban hospital, Turn around time for tests is a critical quality characteristic. Lately you have become concerned that the variability in tum around times from test to test has increased a lot You are not hearing a lot of complaints from your internal customers, but the complaints that you do receive are about tumaround times that are wildiy different from t al averages, In other words, some waits are have gotten really really long even it the quensage wait has not chansed. On the other hand, you' d positive comments from other internal customers thanking you for getting them their test results in much less tiene than nomal. Luckily. your team has been tracking turnaround times using statistical process control. The number in the body of the table is the turnaround time in hours for the most common kind of test. Your lab operates round the clock. You remember from SCM301 that you should always use an x bar and . chart tozether. Which chart is likely to reveal the problem described here? Compute the average or each sample (x bar) and the range of each sample (f) to validate yourself or to help you figure out the answer.-i.e. is it the average or the range that suggests something in the process is changing over time? The averages of the sambles (xbar) are very stable, however the rance is growing drastically. An R clurt would likelv show that the process is going "out of control" The variation (If within esch sample is very stable; however the sample averages ban) are growing drastically. An X bar chart would likely show that the process is soing "out of control" s X bar bar (the center line on chart if we were to make one) k stable So an X bur chart would sugsest to is that the process has gone "out of control" The werage of the ranges ('f bankthe center line on chart if wo were to make one) is stable. This suggests the process has gone out of control. Question 11 Refer to the lab tumaround time data above. If we made an R chart using the data in the table, what is the value for the centerline (R bar)