Q1) Advertisement for particular tax preparation software package claims you can complete your taxes in less than 56 minutes. Random selection of 49 individual's tax preparation times (using software) was collected, and their mean was computed to be 55 minutes. It is known that standard deviation is 4 minutes. Test hypotheses for questions 10, 11, and 12:
H0: μ ≥ 56
Ha: μ < 56(Claim)
i) Calculate the test statistic:
ii) Determine the p-value of the test-statistic:
iii) Is there sufficient evidence to support = claim at significance level alpha = .05? Why?
Engineer suspects that cutting speed (in inches) and feed rate (inches/minute) influence surface finish of metal part. For study engineer collected 4 cutting speeds and 3 feed rates and conducted a 2 factor experiment to get the data in Table with three replications. Carry out ANOVA at α = 0.05 to test for significance of all possible effects.
Table
|
Feed Rate
|
|
Cutting Speed
|
0.10
|
0.20
|
0.30
|
|
100
|
54, 60, 65
|
79, 68, 80
|
99, 88, 94
|
|
200
|
98, 89, 94
|
98, 106, 90
|
100, 98, 108
|
|
300
|
109, 98, 89
|
100, 108, 94
|
99, 82, 102
|
|
400
|
112, 100, 82
|
94, 104, 108
|
98, 116, 106
|