Statistics and Probability with Applications for Engineers and Scientists, Preliminary Edition

Appendix B: Answers to Selected Problems

Chapter 2

Sections 2.1 and 2.2

3. (a) All the students of the graduation class. (b) All the students in the professor's class. (c) GPA.

5. (a) Ratio (b) Ratio (c) Ratio (d) Nominal (e) Ratio (f) Ordinal (g) Ratio (h) Ratio (i) Interval (j) Ratio (k) Ratio (l) Ratio (m) Ordinal (n) Nominal

Section 2.3

3. (b) (1, 2, 3, 4, 5) ~ (24%, 24%, 16%, 22%, 14%) (c) 48%

Section 2.4

3. The line graph does not show any particular pattern.

5. The stem-and-leaf diagram with increment 5 is more informative.

9. (b) On 13 of 31 days, 36 or more patients were treated.

Section 2.5

1. (a) = 120.02, Med = 120.10, no mode. (b) 1.84 (c) approximately symmetric.

3. (a) = 22.356, Med = 23.00 (b) 4.73 (c) 100%

5. (a) = 108.47, Med = 107.50, mode = 100 (b) Range = 20, Var. = 50.10, S = 7.08, CV = 6.53 7. 3.75238 9. (51,100, 60,100), (46,600, 64,600) 11. (a) = 22.650, S = 1.461 (b) (21.189, 24.111), (19.728, 25.572), (18.267, 27.033) (c) 100%, 100%, Chebychev's Inequality is valid.

Sections 2.7 and 2.8

1. (a) = 12.026, S² = 0.289, S = 0.537 (b) Q₁ = 11.753, Q₂ = 12.070, ...