Chapter 13.5, Problem 13.32ACB

Quality control for irrigation data. Refer to Exercise 13.16s (p. 13-31) and the monitoring of irrigation data by the CIMIS. Recall that daily minimum air temperatures (°C) collected hourly during the month of May at the Davis CIMIS station yielded the following summary statistics (where five measurements are collected each hour): $\overline{\stackrel{¯}{x}}={10.16}^{\circ }$ and $\bar{R}={14.87}^{\circ }$.

1. a. Use the information provided to find the lower and upper control limits for an R-chart.
2. b. Suppose that one day in May the air temperature at the Davis CIMIS station had a high of 24.7° and a low of 2.2°. How should the manager of the station respond to this observation?