Chapter 1 - Problem Solving and Critical Thinking - Chapter Summary, Review, and Test - Review Exercises - Page 43: 23

Rounded: 60 Actual: 56.4

Rounding off the numbers, the estimate of the total amount spent is = (21 x 1) + (2 x 12) + (1 x 15) = 21 + 24 + 15 = 60 dollars Actual amount spent by him = (21 x 0.85) + (2 x 11.95) + (1 x 14.65) = 17.85 + 23.9 +14.65 = 56.4 dollars It is a reasonable estimation, as the difference between the 2 answers is only 3.6.