In: Statistics and Probability
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.
Chart:
Time in Examination Rooms (minutes)
Physician 1 Physician 2 Physician 3 Physician 4
34 33 17 28
25 35 30 33
27 31 30 31
31 31 26 27
26 42 32 32
34 33 28 33
21 26 40
29
(a) Calculate the mean for each group and the Turkey test statistic Tcalc for each pair. Provide the critical values for both a = .05 and a = .01. (Input the mean values within the input boxes of the first row and input boxes of the first column. Input Tcalc in the appropriate boxes in the table. Round all answers to 2 decimal places.)
Chart:
Turkey 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 rates:
0.05 _________
0.01 _________
( "______" is where an answer is needed)
count, ni = | 8 | 7 | 7 | 6 | ||||
mean , x̅ i = | 28.375 | 33.00 | 29.00 | 30.67 | ||||
std. dev., si = | 4.5 | 4.9 | 6.9 | 2.6 | ||||
sample variances, si^2 = | 20.554 | 23.667 | 47.667 | 6.667 | ||||
total sum | 227 | 231 | 203 | 184 | 845 | (grand sum) | ||
grand mean , x̅̅ = | Σni*x̅i/Σni = | 30.18 |
SS | df | MS | F | p-value | |
Between: | 92.9 | 3 | 31.0 | 1.2 | 0.321 |
Within: | 605.2 | 24 | 25.2 | ||
Total: | 698.1 | 27 |
Critical value for alpha = 0.05
Level of significance 0.05
no. of treatments,k 4
DF error =N-k= 24
MSE = 25.2170
q-critical value(0.05,4,24)= 3.9013
mean difference | absolute mean difference | std error | critical value | lower limit | upper limit | test stat | p value | result | |
µ1-µ2 | -4.63 | 4.63 | 1.838 | 7.17 | -11.79 | 2.54 | 2.52 | 0.0189 | means are not different |
µ1-µ3 | -0.63 | 0.63 | 1.838 | 7.17 | -7.79 | 6.54 | 0.34 | 0.7367 | means are not different |
µ1-µ4 | -2.29 | 2.29 | 1.918 | 7.48 | -9.77 | 5.19 | 1.20 | 0.2438 | means are not different |
µ2-µ3 | 4.00 | 4.00 | 1.898 | 7.40 | -3.40 | 11.40 | 2.11 | 0.0457 | means are not different |
µ2-µ4 | 2.33 | 2.33 | 1.976 | 7.71 | -5.37 | 10.04 | 1.18 | 0.2491 | means are not different |
µ3-µ4 | -1.67 | 1.67 | 1.976 | 7.71 | -9.37 | 6.04 | 0.84 | 0.4072 | means are not different |
-------------------------
Level of significance 0.01
no. of treatments,k 4
DF error =N-k= 24
MSE = 25.2170
q-critical value(0.01,4,24)= 4.9063
mean difference | absolute mean difference | std error | critical value | lower limit | upper limit | test stat | p value | result | |
µ1-µ2 | -4.63 | 4.63 | 1.838 | 9.02 | -13.64 | 4.39 | 2.52 | 0.0189 | means are not different |
µ1-µ3 | -0.63 | 0.63 | 1.838 | 9.02 | -9.64 | 8.39 | 0.34 | 0.7367 | means are not different |
µ1-µ4 | -2.29 | 2.29 | 1.918 | 9.41 | -11.70 | 7.12 | 1.20 | 0.2438 | means are not different |
µ2-µ3 | 4.00 | 4.00 | 1.898 | 9.31 | -5.31 | 13.31 | 2.11 | 0.0457 | means are not different |
µ2-µ4 | 2.33 | 2.33 | 1.976 | 9.69 | -7.36 | 12.03 | 1.18 | 0.2491 | means are not different |
µ3-µ4 | -1.67 | 1.67 | 1.976 | 9.69 | -11.36 | 8.03 | 0.84 | 0.4072 | means are not different |
Please let me know in case of any doubt.
Thanks in advance!
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