A project is looking at the time it takes field teams to repair faults in air conditioning systems on customer

sites. Five consecutive repair tasks were sampled every day for $20$ days, and the measured times in hour

are shown in the following table.Assume that $6$ hours is the maximum allowable time by the customer. To avoid over$-$resourcing the repair

teams are organized so that it takes at least $3$ hours to finish a repair task. Use the given data to:

$1)$ Verify whether or not the process is under control? $($use the X$-$bar and R$-$bar charts$)$

$2)$ Estimate the potential and actual process capabilities as well as process Sigma level $($given a

$1\mathrm{.}5$

shift from the target$).$