Question

Use MegaStat, MINITAB, or another software package to perform Tukey’s test for significant pairwise differences. Perform the test using both the 5 percent and 1 percent levels of significance.

One particular morning, the length of time spent in the examination rooms is recorded for each patient seen by each physician at an orthopedic clinic.

Time in Examination Rooms (minutes)
Physician 1	Physician 2	Physician 3	Physician 4
35	33	16	28
22	38	32	35
29	35	31	32
32	34	24	28
28	40	34	33
32	32	26	34
19		27	43
		28

  Click here for the Excel Data File

(a) Calculate the mean for each group and the Tukey test statistic T_calc for each pair. Provide the critical values for both α = .05 and α = .01. (Input the mean values within the input boxes of the first row and input boxes of the first column. Input T_calc in the appropriate boxes in the table. Round all answers to two decimal places.)

Post hoc analysis:

Tukey simultaneous comparison t-values (d.f. = 24)
		Physician 3	Physician 1	Physician 4	Physician 2
Physician 3
Physician 1
Physician 4
Physician 2
Critical values for experimentwise error rate:
		0.05
		0.01

Answer 1

One-way ANOVA:

Source DF SS MS F P
C2 3 316.6 105.5 4.06 0.018
Error 24 623.1 26.0
Total 27 939.7

Mean time for Physician 2 and Physician 3 are different at 5% level whereas at 1% level of significance all are equal.