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 panelemergency condition combination. The time (in seconds) required to stabilize the emergency condition was recorded. The following table gives the resulting data 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	17.333330
B	18.375000	2	24.500000
C	25.625000	3	32.166670
		4	13.333300

Analysis of Variance
Source	DF	Sum of Squares	Mean Square	F Ratio
Model	11	1,466.3333	133.303	30.1818
Error	12	53.0000	4.417	Prob > F
C. Total	23	1,519.3333		<.0001*

Effect Tests
Source	Nparm	DF	Sum of Squares	F Ratio	Prob > F
Panel	2	2	211.5833	23.9528	<.0001*
Condition	3	3	1,238.3333	93.4591	<.0001*
Panel* Condition	6	6	16.4167	0.6195	0.7119

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	3.12500	1.050793	2.97	0.0290*	0.3217	5.92826
A	C	4.12500	1.050793	3.93	0.0053*	6.9283	1.32174
B	C	7.25000	1.050793	6.90	< .0001*	10.0533	4.44674

Tukey HSD All Pairwise Comparisons

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

Condition	-Condition	Difference	Std Error	t Ratio	Prob>|t|	Lower 95%	Upper 95%
1	2	7.1667	1.213352	5.91	0.0004*	10.7689	3.5645
1	3	14.8333	1.213352	12.23	< .0001*	18.4355	11.2311
1	4	4.0000	1.213352	3.30	0.0283*	0.3978	7.6022
2	3	7.6667	1.213352	6.32	0.0002*	11.2689	4.0645
2	4	11.1667	1.213352	9.20	< .0001*	7.5645	14.7689
3	4	18.8333	1.213352	15.52	< .0001*	15.2311	22.4355

Click here for the Excel Data File

(a) Interpret the interaction plot in Figure 12.12. Then test for interaction with = .05.

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

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

(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.)

(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.)

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

(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.)