5 points 4-172). Accountants at the firm Walker and Walker believed that several traveling executives submit unusually high travel vouchers when they return from business trips. The accountants took a sample of 200 vouchers submitted from the past year, they then developed the following multiple regression equation relating expected travel cost (Y) to number of days on the road (X) and distance traveled (X) in miles 9-590-548 5X +5.040x2 The coefficient of correlation computed was 0.63 c(2). What percentage of variability in the cost of the trip is NOT explained by this model? .82 ..46 .54 23