Erie Furniture Store, a fictional company, buys chests of drawers made out of teakwood. One of the features that determines whether a chest of drawers is of good quality is the presence or absence of dust panels (thin sheets of wood) between the drawers in the body of a chest or desk. These panels make the products structurally stronger and also keep dust away from the contents inside of the drawers. To monitor the quality of the Brazilian firm that supplies the chests, Erie Furniture collected the following data on the number of chests with missing dust panels. The data were gathered over the course of 15 months, and each sample collected contained 100 chests: Sample 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15
No. defective 11 8 7 8 5 6 9 11 6 8 4 13 4 5 8

Required:
a. Construct a p-chart with 3Ï limits, and determine whether the process is in control. Round your answers to three decimal places.
b. The process is in control. The process is not in control.