Construct the appropriate control chart for the 11 observations, and determine if the process is in control using two sigma limits. No. of defects per unit for the observations are: 4, 4, 11, 1, 11, 1, 10, 3, 7, 1, 7.
a. 4 observations out of control b. 3 observations out of control c. Under control d. 2 observations out of control