I am interested in looking at the salaries of professors to see if they are cons
ID: 468854 • Letter: I
Question
I am interested in looking at the salaries of professors to see if they are consistently paid similarly, regardless of location and specialties. Random samples of size four were taken and produced the following data:
Sample
Average
Range
1
95751.6
33196
2
74659.8
19028
3
64632.2
17445
4
64964
18169
5
88361.6
29142
6
73477.4
16012
7
63611.4
11595
8
64352
14901
a. Find the UCL for the R chart.
b. Find the LCL for the R chart.
c. Is this chart in control? Why/why not?
d. Find the UCL for the -chart.
e. Find the LCL for the -chart.
f. Is this process in control? Why/why not?
Sample
Average
Range
1
95751.6
33196
2
74659.8
19028
3
64632.2
17445
4
64964
18169
5
88361.6
29142
6
73477.4
16012
7
63611.4
11595
8
64352
14901
Explanation / Answer
1. UCL = D4*R
where R is the average range = Sum of all ranges/8 = 19936
D4 = 1.864 (from the table)
UCL = 1.864*19936 = 37160
2. LCL = D3*R
D3 = 0.136
So, LCL = 0.136*19936 = 2711
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.