18. Construction Projects An analyst wanted to predict the time required to complete a construction project (y) using four variables—size of the contract 1 x (in $1000 units), number of workdays adversely affected by the weather 2 x , number of subcontractors involved in the project 4 x , and a variable 3 x that measured the presence ( 1) 3 x 5 or absence

( 0) 3 x 5 of a workers’ strike during the construction.

Fifteen construction projects were randomly chosen, and each of the four variables as well as the time to completion were measured.

An analysis of these data using a first-order model in 1 x , 2 x , 3 x , and 4 x produced the following printout. Give a complete analysis of the printout and interpret your results. What can you say about the apparent contribution of 1 x and 2 x in predicting y?

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y x X X3 XA 29 60 15 80 60 100 10 50 70 200 70842 10 100 14 0 12 1 15 50 4 0 75 500 15 1 30 75 5 0 45 750 10 0 90 1200 20 1 12 7 70 5 0 21 80 3 0 28 300 8 0 50 2600 14 1 7805-326023683 10 11 12 10 13 30 110 7 0 4