quality assurance question and excel

ETM 603-Quality Assurance Course Instructor: Dr. K. Jenab

Student Name: Student ID#.............................................................................

Probability Plot Illustration in Class

1. X is normally disturbed with MU=20, Sigma=2.551. Find P(X<=20)? (Note: Use Normal table in the text book or In the internet).

2- Using Excel function (=NORMSINV()), find the Z value for probability 0.97500

3- Given the below table, construct the normal probability plot. What is your conclusion?

Ref.: https://www.youtube.com/watch?v=3BqWqECOqEc

Week	Costbar
21	305
22	282
23	305
24	296
25	314
26	295
27	287
28	301
29	298
30	311
31	310
32	292
33	305
34	299
35	304
36	310
37	304
38	305
39	333
40	328