STA 144 Homework 1

Work on the following problem set from chapters 1-2. Do not delete any of the questions.

Chapter 1

1. Search your local newspaper or online multimedia for the results of a survey or interview about any topic. Summarize the results and do the best job you can of describing how the researchers who were involved, or the authors of the survey, came to the conclusions they did. It may or may not be apparent. Once you have some idea of what they did, try to speculate about other ways the same information might be collected, organized, and summarized.

2. Make a list of 10 things that you would like to measure and speculate how you might do that. For example, let us say some of your coursework involves the incidence of crime in suburban settings. What might you like to measure to know more about those outcomes? How would you measure these things, and which measures do you think would be “best” (do not worry about how to define that loaded word).

3. Finally, as your last in this first set of exercises, come up with five of the most interesting questions you can about your own area of study or interest. Do your best to come up with questions for which you would want real, existing information or data. Be a scientist!

Chapter 2

1. Using SPSS, compute the mean, median, and mode for the following set of 40 reading scores. Show your work by copying and pasting a copy of the output below.

31 32 43 42

24 34 25 44

23 43 24 36

25 41 23 28

14 21 24 17

25 23 44 21

13 26 23 32

12 26 14 42

14 31 52 12

23 42 32 34

2. Compute the mean, median, and mode for the following three sets of scores saved as Chapter 2 Data Set 2. Use a computer program such as SPSS. Copy and paste a copy of the output below.

Score 1 Score 2 Score 3

3 34 154

7 54 167

5 17 132

4 26 145

5 34 154

6 25 145

7 14 113

8 24 156

6 25 154

5 23 123

3. Compute the means for the following set of scores saved as Chapter 2 Data Set 3 (in appendix C) using SPSS. Copy and paste a copy of the output below.

Hospital Size (number of beds) Infection Rate (per 1,000 admissions)

234 1.7

214 2.4

165 3.1

436 5.6

432 4.9

342 5.3

276 5.6

187 1.2

512 3.3

553 4.1

4. You are the manager of a fast-food restaurant. Part of your job is to report to the boss at the end of each day which special is selling best. Use your vast knowledge of descriptive statistics and write one paragraph to let the boss know what happened today. Here are the data. Don’t use SPSS to compute important values; rather, do it by hand. Be sure to include a copy of your work.

Special Number Sold Cost

Huge Burger 20 $2.95

Baby Burger 18 $1.49

Chicken Littles 25 $3.50

Porker Burger 19 $2.95

Yummy Burger 17 $1.99

Coney Dog 20 $1.99

Total specials sold 119

5. Imagine yourself as the CEO of a huge corporation, and you are planning an expansion. You’d like your new store to have some of the same typical numbers as the other three that are under your empire. By hand, provide some idea of what you want the store to look like. And remember that you have to select whether to use the mean, the median, or the mode as an average. Good luck, young Jedi.

Average Store 1 Store 2 Store 3 New Store

Sales (in thousands) 323.6 234.6 308.3

Number of items purchased 3,454 5,645 4,565

Number of visitors 4,534 6,765 6,654

6. Here are the top 10 season hitting percentages for members of two baseball teams, and you must determine which is the best-hitting team, defined as the average. You have to decide which type of average you use and why. Do this by using SPSS.

Team 1 Team 2

0.345 0.243

0.254 0.378

0.278 0.312

0.331 0.298

0.267 0.287

0.465 0.387

0.189 0.301

0.312 0.412

0.365 0.254

0.287 0.342

7. Under what conditions would you use the median rather than the mean as a measure of central tendency? Why? Provide an example of two situations in which the median might be more useful than the mean as a measure of central tendency.

8. Suppose you are working with a data set that has some very “different” (much larger or much smaller than the rest of the data) scores. What measure of central tendency would you use and why?

9. For this exercise, use the following set of 16 scores (ranked) that consists of income levels ranging from about $50,000 to about $200,000. What is the best measure of central tendency and why?

$199,999

$98,789

$90,878

$87,678

$87,245

$83,675

$77,876

$77,743

$76,564

$76,465

$75,643

$66,768

$65,654

$58,768

$54,678

$51,354

10. Use the data in Chapter 2 Data Set 4 (in appendix C of your textbook), compute (use SPSS) the average attitude scores (with a score of 10 being positive and 1 being negative) for three groups of individuals with varying degrees of experience with urban transportation.

11.Take a look at the following set of the average hours of work per week for two groups of adolescents and compute the more appropriate average score.

Child Group 1 Group 2

1 Lots Little

2 Little Somewhat

3 Somewhat Somewhat

4 Little Little

5 Little Somewhat

6 Little Lots

7 Little Lots

8 Little Somewhat

9 Somewhat Somewhat

10 Lots Somewhat