Consider the data collected in the first six production cycles of the process described in problem 11-2. Assume that the standard deviations for each of the four product models are known and the targets and standard deviations are as follows.

a. For each observation compute the Q statistics and construct a pair of Z charts. Interpret the control status of this process.
Refer to attached spreadsheet for calculations
b. Using the charts you constructed in part a, add the data for the next 6 cycles shown in problem 11-2c. Has the control status changed? Explain
c. How do your conclusions in parts a and b compare with the conclusions you reached for this process in problem 11-2b and 11-2c? Can you explain any inconsistencies?

Standard Mod el Target Deviation 15 20 24 30 0.2 0.4 0.6