A study compared three display panels used by air traffic controllers. Each display panel was tested for four different simulated emergency conditions. Twenty-four highly trained air traffic controllers were used in the study. Two controllers were randomly assigned to each display panel--emergency condition combination. The time (in seconds) required to stabilize the emergency condition was recorded. The following table gives the resulting dta and the JMP output of a two-way ANOVA of the data

Emergency Condition

Display Panel 1 2 3 4

A 17 25 31 14

14 24 34 13

B 15 22 28 9

12 19 31 10

C 21 29 32 15

24 28 37 19

Least Squares Means Estimates

Panel Estimate Condition Estimate

A 21.500000 1 17.166667

B 18.250000 2 24.500000

C 25.625000 3 32.166667

4 13.333333

Analysis of Variance

Source DF Sum of Squares Mean Square F Ratio

Model 11 1482.4583 134.769 32.6713

Error 12 49.5000 4.125 Prob > F

C. Total 23 1531.9583 <.0001*

Effect Tests

Source Nparm DF Sum of Squares F Ratio Prob > F

Panel 2 2 218.5833 26.4949 <.0001*

Condition 3 3 1247.4583 100.8047 <.0001*

Panel* Condition 6 6 16.4167 0.6633 0.6809

Tukey HSD All Pairwise Comparisons

Quantile = 2.66776, Adjusted DF = 12.0, Adjustment = Tukey

Panel -Panel Difference Std Error t Ratio Prob>[t] Lower 95% Upper 95%

A B 3.25000 1.015505 3.20 0.0194* 0.5409 5.95912

A C -4.12500 1.015505 -4.06 0.0042* -6.8341 -1.41588

B C -7.37500 1.015505 -7.26 <.0001* -10.0841 -4.66588

Tukey HSD All Pairwise Comparisons

Quantile = 2.9688, Adjusted DF = 12.0, Adjustment = Tukey

Condition -Condition Difference Std Error tRatio Prob>[t] Lower 95% Upper 95%

1 2 -7.3333 1.172604 -6.25 0.0002* -10.8146 -3.8521

1 3 -15.0000 1.172604 -12.79 <.0001* -18.4812 -11.5188

1 4 3.8333 1.172604 3.27 0.0297* 0.3521 7.3146

2 3 -7.6667 1.172604 -6.54 0.0001* -11.1479 -4.1854

2 4 11.1667 1.172604 9.52 <.0001* 7.6854 14.6479

3 4 18.8333 1.172604 16.06 <.0001* 15.3521 22.3146

Emergency Condition

1 2 3 4

A 17 25 31 14

14 24 34 13

Dis. B 15 22 28 9

Panel 12 19 31 10

C 21 29 32 15

24 28 37 19

a. Interpret the interaction plot in Figure 12.12. Then test for interaction with a = 0.5.

Panel B requires ________ to stabilize the emergency condition.

F(int) = .6633, p-value = .6809; __________ reject H0, no interaction exists.

b. Test the significance of display panel effects with a = .05.

F= 26.4949, p-value = 0.001; ______________ H0

c. Test the significance of emergency condition effects with a = .05

F = 100.8047, p-value = .0001; _________H0

d. Make pairwise comparisons of display panels A, B, and C by using Tukey simultaneous 95 percent confidence intervals. (Round your answers to 4 decimal places. Negative amounts should be indicated by a minus sign.)

uA - uB: [_________, ___________]

uA - uC: [_________, ___________]

uB - uC: [_________, ___________]

e. Make pairwise comparisons of emergency conditions 1,2,3, and 4 by using Tukey simultaneous 95 percent confidence intervals. (Round your answers to 4 decimal places. Negative amounts should be indicated by a minus sign.)

u1 - u2 [____________, ____________]

u1 - u3 [____________, ____________]

u1 - u4 [____________, ____________]

u2 - u3 [____________, ____________]

u2 - u4 [____________, ____________]

u3 - u4 [____________, ____________]

f. Which display panel minimizes the time required to stabilize an emergency condition? Does your answer depend on the emergency condition? Why?

_________ minimizes the time required to stabilize an emergency condition.

_________, there is ____________ interaction.

g. Calculate a 95 percent (individual) confidence interval for the mean time required to stabilize emergency condition 4 using display panel B. (Round your answers to 2 decimal places.)

Confidence Interval [_________, __________]