Statistics for Engineering and the Sciences Student Solutions Manual

William M. Mendenhall, Terry L. Sincich, Nancy S. Boudreau

• Publisher: Chapman and Hall/CRC
• Year: 2016
• eBook ISBN: 9781498731997
• Edition: 6
• Topic: Mathematics
• Subtopic: Physics
• Index: Mathematics

A companion to Mendenhall and Sincich's Statistics for Engineering and the Sciences, Sixth Edition, this student resource offers full solutions to all of the odd-numbered exercises.

1

Introduction

1.1 a. The population of interest to the researchers is the population of all young women who recently participated in a STEM program.

b. The sample is the set of 159 young women who were recruited to complete an on-line survey.

c. We could infer that approximately 27% of all young women who recently participated in a STEM program felt that participation in the STEM program increased their interest in science.

1.3 There are two populations – male students at Griffin University who were video game players and male students at Griffin University who were not video game players. There were two samples — those male students in the 65 chosen who were video game players and those male students in the 65 chosen who were not video game players.

1.5 a. The experimental units for this study are the earthquakes.

b. The data from the 15 earthquakes represent a sample. There are many more than 15 earthquakes from around the world. Only 15 of the many were studied.

1.7 a. The variable measured is the level of carbon monoxide gas in the atmosphere. The experimental unit is the atmosphere at the Cold Bay, Alaska, weather station each week.

b. If we are interested in only the weekly carbon monoxide values at the Cold Bay station for the years 2000-2002, then this data represents the population because all that data were collected.

1.9 a. Sampling method would be qualitative.

b. Effective stress level would be quantitative.

c. Damping ratio would be quantitative.

1.11 a. Town where sample was collected is qualitative.

b. Type of water supply is qualitative.

c. Acidic level is quantitative.

d. Turbidity level is quantitative.

e. Temperature is quantitative.

f. Number of fecal coliforms per 100 milliliters is quantitative.

g. Free chlorine-residual is quantitative.

h. Presence of hydrogen sulfide is qualitative.

1.13 a. The experimental units are the smokers.

b. Two variables measured on each smoker are screening method and age at which scanning method first detects a tumor.

c. Screening method is qualitative and age is quantitative.

d. The inference is which screening method (CT or X-ray) is more effective in pinpointing small tumors.

1.15 Answers will vary. First, we number the wells from 1 to 223. We will use Table 1, Appendix B to select the sample of 5. Start in column 8, row 11, and look at the first 3 digits. We proceed down the column until we select 5 numbers between 1 and 223: 58, 176, 136, 47, and 153. Thus, wells numbered 47, 58, 136, 153, and 176 will be selected.

1.17 Answers will vary. First, we number the weeks from 1 to 590. Using the MINITAB random sample procedure, the following sample is selected:

Weeks	Sample
1	568
2	584
3	329
4	379
5	54
6	104
7	171
8	439
9	192
10	590
11	81
12	67
13	230
14	56
15	154

The 15 weeks with the numbers listed in the Sample column will be selected.

1.19 a. The population of interest is all computer security personnel at all U.S. corporations and government agencies.

b. The data-collection method is a survey of 5,412 firms. Only 351 computer security personnel responded. Since this was a survey, the computer security personnel elected to either respond or not. Because only 351 of the 5,412 firms survey responded, there could be a nonresponse bias. In addition, the security personnel chose whether to respond or not.

c. The variable measured is whether or not unauthorized use of the computer system occurred at the firm during the year. This variable is qualitative because the response would be yes or no.

d. Because 41% of the sample admitted that there was unauthorized use of their computer system, we can infer that approximately 41% of all firms had unauthorized use of their computer systems during the year.

1.21 First, suppose we number all of the intersections from 1 to 5,000. Then, we will use a random number generator to select 50 numbers between 1 and 5,000. The intersections wit...

Table of contents

• Cover
• Half Title
• Title Page
• Copyright Page
• Table of Contents
• 1. Introduction
• 2. Descriptive Statistics
• 3. Probability
• 4. Discrete Random Variables
• 5. Continuous Random Variables
• 6. Bivariate Probability Distributions and Sampling Distributions
• 7. Estimation Using Confidence Intervals
• 8. Tests of Hypotheses
• 9. Categorical Data Analysis
• 10. Simple Linear Regression
• 11. Multiple Regression Analysis
• 12. Model Building
• 13. Principles of Experimental Design
• 14. The Analysis of Variance for Designed Experiments
• 15. Nonparametric Statistics
• 16. Statistical Process and Quality Control
• 17. Product and System Reliability
• Appendix A: Matrix Algebra