Consider the data set shown in Table 18.5.7, indicating hourly summaries of the temperature for a baking oven measured four times per hour.
a. Draw an and an R chart for each day.
b. For each day, summarize the charts. In particular, was the process in control? How do you know?
c. For each day, tell what action is appropriate.
d. A new product requires that the temperature be constant to within plus or minus 10 degrees. Based on the €œin control€ control charts from part a, do you think that these ovens can be used for this purpose? Why or why not?

TABLE 18.5.7 Average and Range of Temperatures Taken Four Times per Hour Monday Tuesday Wednesday Time 408.65 401.57 395.52 12:00 30.74 25.23 402.92 401.07 405.97 401.70 402.06 403.35 407.82 40030 403.69 399.72 32.72 407.28 22.85 35.91 398.43 389.97 40237 406.29 407.77 398.22 408.42 405.04 404.12 404.44 407.19 407.43 412.60 413.40 407.26 402.97 387.44 414.39 401.25 400.43 399.31 403.14 403.07 403.66 404.05 399.00 30.56 32.63 21.56 25.29 14.32 39.70 19.11 28.89 37.26 33.30 400.82 401.96 399.94 401.01 399.67 401.67 413.30 412.47 10:00 391.20 20.08 13.29 35.90 12.32 12:00 398.59 21.89 1434 18.62 27.96 30.34 29.53 12.62 39437 409.59 4038 48.70 25.75 394.58 37.57 33.52 45.69 40.52 39.77 6:00 407.01 8:00 9:00 10:00 11:00 421.90 429.67 422.75 422.56 424.39 21.75 24.30 25.79 15.28 16.64 404.93 391.82 393.96 421.68 67.03 84.53 92.92