TABLE 17-7 A Supplier of Silicone Sheets for Producers of Computer Chips

Short Answer

TABLE 17-7
A supplier of silicone sheets for producers of computer chips wants to evaluate her manufacturing process. She takes samples of size 5 from each day's output and counts the number of blemishes on each silicone sheet. The results from 20 days of such evaluations are presented below.
She also decides that the upper specification limit is 10 blemishes.
-Referring to Table 17-7, an chart is to be used for the number of blemishes. One way to obtain the control limits is to take the grand mean and add and subtract the product of A₂ times the average of the sample ranges. For this data set, the value of A₂ is ________.