Statistical Process Control

an average life of $50$ hours, about $10\%$ longer than competitors' models. To raise the lifetime above this level would require a new level of technology not available to West. Nevertheless, he is concerned enough to set up hourly assembly line checks. He decides to take size$-5$ samples of $9-$volt batteries for each of the next $25$ hours to create the standards for control chart limits $($see the following table$)$:Use Excel to calculate the upper and lower control limits$,$ the x bar control chart and the R chart.

Are the processes in control?