Question

Is the transportation mode used to ship goods independent of type of industry? Suppose the following contingency table represents frequency counts of types of transportation used by the publishing and the computer hardware industries. Analyze the data by using the chi-square test of independence to determine whether type of industry is independent of transportation mode. Let α = 0.05.

	Transportation Mode
Industry	Air Train Truck Publishing 31 12 40 Computer Hardware 5 6 24

Appendix A Statistical Tables

(Round the intermediate values to 2 decimal places. Round your answer to 2 decimal places.)

Observed χ2 =  
Transportation mode is                                                           not independent or independent of industry.

Answer 1

Applying chi square test of independence:

Expected	Ei=row total*column total/grand total	Air	train	truck	Total
	publishing	25.320	12.661	45.017	82.9979661
	computer	10.678	5.339	18.983	35
	total	35.9979661	18	64	117.9979661
chi square    χ2	=(Oi-Ei)2/Ei	Air	train	truck	Total
	publishing	1.274	0.035	0.559	1.8678
	computer	3.019	0.082	1.326	4.4270
	total	4.2934	0.1164	1.8850	6.295
test statistic X2 =		6.29
p value =		0.043

since p value <0.05

ransportation mode is not independent of industry.