Chapter 5 Control Charts For Variables

Section 4. The Shewhart Control Chart For Individual Measurements (ATTENDANCE 4)915.4 The Shewhart Control Chart For IndividualMeasurementsIn this section, we look at Shewhart control charts for individual measurements.Exercise 5.3 (Shewhart control charts for individual measurements)Thirty (30) individual ice cream treats are weighed (in ounces).SAS program: att4-5-4-icecream-irchart5.4 8.6 9.5 4.0 0.9 5.2 5.52.8 5.3 6.3 3.9 9.8 6.9 9.85.1 8.4 1.0 1.2 7.1 5.7 0.61.0 3.0 6.0 7.2 8.0 5.9 0.07.9 3.41. Individual measurement chart and moving range MR chartFrom SAS, both the individual chart and moving range MR chart for the icecream weight is (choose one) in / out of statistical control because there areno out-of-control signals, runs, trends, or cycles.2. Moving range, MR iSince the weight of the first ice cream treat is x 0 = 5.4 and the weight of thesecond ice cream treat is x 1 = 8.6, the first moving range (based on n = 2observations) isMR 1 = |x 1 − x 0 | = |8.6 − 5.4| = 3.2and so the second moving range isMR 2 = |x 2 − x 1 | = |9.5 − 8.6| =(choose one) 0.5 / 0.9 / 1.6The average of all moving ranges is denoted MR.3. (LCL, UCL) for individual measurement chartFrom the SAS graph, ¯x = (choose one) 5.2 / 10.5 / 10.6The upper control limit and the lower control limit for the individual measurementchart are,(choose one)¯x ± 3ˆσ = ¯x ± 3 ¯R/d 2= ¯x ± 3MR/d 2= 5.2 ± 3(3.22069/1.128)= (LCL, UCL) =