A large national producer of cookies and baked goods uses a c chart to monitor the number of chocolate chips in its chocolate chip cookies. The company would like to have an average of six chips per cookie. One cookie is sampled each hour. The results of the last 12 hours were Number of Chips Number of Chips Hour per Cookie Hour per Cookie 1 7 7 3 2 4 8 6 3 3 9 3 4 3 10 2 5 5 11 4 6 4 12 4

a. Assuming a target value of c  6, what are the upper and the lower control limits for a c chart?

b. Are the 12 observations consistent with a target value of c  6? If those 12 observations constitute a baseline, what upper and lower control limits result?

(Use the normal approximation for your calculations.)