As part of an air pollution study, visibility in air wasmeasured in three months at two altitude level.

Altitude (m)	Visibility in town air (km)
Jan	Jun	Dec
0	13.5	3.8	14.3
0	17.2	3.3	16.9
0	18.1	7.2	21.0
0	14.3	10.5	19.7
0	19.5	9.1	18.0
50	14.5	2.8	16.5
50	17.4	3.1	16.8
50	19.1	4.2	21.6
50	20.3	6.5	19.2
50	18.5	9.1	17.0

Question11

Given that the data neither follow normal distribution nor haveequal variance, what is the appropriate test to determine ifvisibility varied with different months and altitude.

Select one:

a. Kruskal-Wallis Test

b. Two independent sample t test

c. Two-way ANOVA

d. Scheirer-Ray-Hare Test

Question12

What are the degree of freedom for the altitude, month and error(Within) respectively?

Select one:

a. 1, 2, 2

b. 1, 2, 24

c. 1, 2, 4

d. 2, 3, 5

e. 2, 3, 29

Question13

What is the conclusion for the variable altitude?

Select one:

a. Air visibility is unequal between different heights(calculated statistics = 0.015, p-value < 0.001)

b. Air visibility is equal between different heights (calculatedstatistics = 0.001, p-value > 0.05)

c. Air visibility is unequal between different heights(calculated statistics = 0.004, p-value < 0.05)

d. Air visibility is equal between different heights (calculatedstatistics = 0.015, p-value > 0.05)

Question14

What is the conclusion for the variable Month?

Select one:

a. Air visibility is unequal among different months (calculatedstatistics = 9.72, 0.001 < p-value < 0.01)

b. Air visibility is unequal among different months (calculatedstatistics = 9.72, p-value < 0.001)

c. Air visibility is unequal among different months (calculatedstatistics = 25.98, p-value < 0.001)

d. Air visibility is equal among different months (calculatedstatistics = 25.98, p-value > 0.05)

Question15

What is the conclusion for the interaction effect betweenaltitude and Month?

Select one:

a. Interaction effect exists between altitude and Month(calculated statistics = 0.75, p-value < 0.05)

b. Interaction effect exists between altitude and Month(calculated statistics = 0.75, p-value < 0.01)

c. No interaction effect between altitude and Month (calculatedstatistics = 0.28, 0.05 < p-value < 0.1)

d. No interaction effect between altitude and Month (calculatedstatistics = 0.28, 0.75 < p-value < 0.90)