Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

(TCO 3) Twenty samples of subgroup size of 5 ( n = 4) were collected for a varia

ID: 2930856 • Letter: #

Question

(TCO 3) Twenty samples of subgroup size of 5 (n = 4) were collected for a variable measurement. Determine the upper control limit (UCL) for an R-chart if the mean of the sample ranges equals 6.4.

Factors for calculating control limits:
n             A2           D3           D4
2              1.880     0              3.267
3              1.023     0              2.574
4              0.729     0              2.282
5              0.577     0              2.114
6              0.483     0              2.004

Explanation / Answer

D4 is used for UCL of R chart

For n = 4, D4 = 2.282

UCL = x_bar * D4 = 6.4*2.282 = 14.6048