Statistics and Probability with Applications for Engineers and Scientists Using MINITAB, R and JMP, 2nd Edition

BAnswers 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

1. (b) (1, 2, 3, 4, 5) ∼ (24%, 24%, 16%, 22%, 14%) (c) 48%. 3. (b) (1, 2, 3, 4, 5) ∼ (30.56%, 22.22%, 13.89%, 8.33%, 25%) (c) 44.45%.

Section 2.4

3. The line graph does not show any particular pattern. There are some dips and peaks which are occurring randomly. 5. The stem‐and‐leaf diagram with increment 5 is more informative. 9. (b) 13 days. 11. Ninety percent of the parts have life span between 20 and 48 months. Only one out of 30 parts has a life span more than 50 months. Two out of 30 parts have life spans less than 20 months. 15. (b) Median consumption of electricity in kilowatt‐hours is 248.5 kWh, maximum consumption is 310 kWh, and minimum consumption is 206 kWh.

Section 2.5

1. (a) , Med =  120.10, mode =  120.1 (b) 1.84 (c) approximately symmetric. 3. (a)  =  22.356, Med =  23.00 (b) 4.73 (c) 100%. 5. (a) , Med =  107.50, mode =  100 (b) Range =  ...