2.72 For the situation and data described in Exercise 2.71, and using data fi le XR02071,

a. Construct a simple tabulation in which the counts are according to which company supplied the electrical/

motor components.

b. Construct a cross-tabulation describing the 100 compressors tested, using electrical/motor supplier and fi nal assembly technician as the categorization variables.

c. Construct a display showing the average pressure

(psi) exerted according to electrical/motor supplier and fi nal assembly technician. Which combination of electrical/motor supplier and fi nal assembly technician seems to result in the highest average pressure exerted? The lowest pressure exerted?

d. Based on the crosstab and means in part (c), would it seem that the two technicians might not be equally adept at the fi nal assembly task? Explain your answer.