/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none}

91影视

Performance of stock screeners.Investment companies provide their clients with automated tools鈥攃alled stock screeners鈥攖o help them select a portfolio of stocks to invest in. The American Association of Individual Investors (AAII) provides statistics on stock screeners at its Website, www.aaii.com. The next table lists the annualized percentage return on investment (as compared to the Standard & Poor鈥檚 500 Index) for 13 randomly selected stock screeners. (Note:A negative annualized return reflects a stock portfolio that performed worse than the S&P 500.)

(9.0, -.1, -1.6, 14.6, 16.0, 7.7, 19.9, 9.8, 3.2, 24.8, 17.6, 10.7, 9.1)

a.Compute the mean for the data set. Interpret its value.

b.Compute the median for the data set. Interpret its value.

Short Answer

Expert verified

a) Mean = 10.82

b) Median = 9.8

Step by step solution

01

Computing and Interpreting the Mean

Mean=SumofallvaluesNumberofvalues

Mean=9.0+-1+-1.6+14.6+16.0+7.7+19.9+9.8+3.2+24.8+17.6+10.7+9.113=140.713=10.82

As the mean is 10.82, the average annualized percentage return on investments is 10.82%for a portfolio of 13 stocks that were randomly selected.

02

Calculating and Analyzing the Median

By arranging the data in ascending order we get,

(-1.6, -0.1, 3.2, 7.7, 9.0, 9.1, 9.8, 10.7, 14.6, 16.0, 17.6, 19.9, 24.8)

9.8 lies in the middle of the distribution. Hence, 9.8 is the median.

Half of the annualized percentage return on investment is less than 9.8, and half is more than 9.8.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Network server downtime.A manufacturer of network computer server systems is interested in improving its customer support services. As a first step, its marketing department has been charged with the responsibility of summarizing the extent of customer problems in terms of system downtime. The 40 most recent customers were surveyed to determine the amount of downtime (in hours) they had experienced during the previous month. These data are listed in the table.

Customer Number

Downtime

Customer Number

Downtime

230

12

250

4

231

16

251

10

232

5

252

15

233

16

253

7

234

21

254

20

235

29

255

9

236

38

256

22

237

14

257

18

238

47

258

28

239

0

259

19

240

24

260

34

241

15

261

26

242

13

262

17

243

8

263

11

244

2

264

64

245

11

265

19

246

22

266

18

247

17

267

24

248

31

268

49

249

10

269

50

a.Construct a box plot for these data. Use the information reflected in the box plot to describe the frequency distribution of the data set. Your description should address central tendency, variation, and skewness.

b.Use your box plot to determine which customers are having unusually lengthy downtimes.

c.Find and interpret the z-scores associated with the customers you identified in part b.

Hotels鈥 use of ecolabels.Ecolabels such as Energy Star, Green Key, and Audubon Internationalare used by hotels to advertise their energy-saving and conservation policies. The Journal of Vacation Marketing(January 2016) published a study to investigate how familiar travelers are with these ecolabels and whether travelers believe they are credible. A sample of 392 adult travelers were administered a questionnaire. One question showed a list of 6 different eco-labels, and asked, 鈥淗ow familiar are you with this ecolabel, on a scale of 1 (not familiar at all) to 5 (very familiar).鈥 Summarized results for the numerical responses are given in the table.

a.Give a practical interpretation of the mean response for Energy Star.

b.Give a practical interpretation of the median response for Energy Star.

c.Give a practical interpretation of the response mode for Energy Star.

d.Based on these summary statistics, which ecolabel appears to be most familiar to travelers?

Ecolabel

Mean

Median

Mode

Energy Star

4.44

5

5

TripAdvisor

3.57

4

4

Green Leaders Audubon

2.41

2

1

International U.S Green

2.28

2

1

Building Council Green Business

2.25

2

1

Green Key

2.01

1

1

Treating psoriasis with the 鈥淒octorfish of Kangal.鈥漃soriasis is a skin disorder with no known cure and noproven effective pharmacological treatment. An alternative treatment for psoriasis is ichthyotherapy, also known as therapy with the 鈥淒octorfish of Kangal.鈥 Fish from the hot pools of Kangal, Turkey, feed on the skin scales of bathers, reportedly reducing the symptoms of psoriasis. In one study, 67 patients diagnosed with psoriasis underwent 3 weeks of ichthyotherapy (Evidence-Based Research in Complementary and Alternative Medicine,December 2006). The Psoriasis Area Severity Index (PASI) of each patient was measured both before and after treatment. (The lower the PASI score, the better is the skin condition.) Box plots of the PASI scores, both before (baseline) and after 3 weeks of ichthyotherapy treatment, are shown in the accompanying diagram.

a.Find the approximate 25th percentile, the median, and the 75th percentile for the PASI scores before treatment.

b.Find the approximate 25th percentile, the median, and the 75th percentile for the PASI scores after treatment.

c.Comment on the effectiveness of ichthyotherapy in treating psoriasis.

Explain how the relationship between the mean and median provides information about the symmetry or skewness of the data鈥檚 distribution.

Performance-based logistics.Refer to the Journal of Business Logistics(Vol. 36, 2015) study of the factors thatlead to successful performance-based logistics (PBL) projects, Exercise 1.15 (p. 49). Recall that the opinions of a sampleof 17 Department of Defense employees and suppliers weresolicited during interviews. Demographics (current position,organization type, experience) were recorded for each intervieweeand the data are listed in the table below.

a.Find and interpret the mean years of experience for the 17 interviewees.

b.Find and interpret the median years of experience for the 17 interviewees.

c.Find and interpret the mode of the 17 years of experience values.

Interviewee

Position

Organization

Experience(years)

1

Vice president

Commercial

30

2

Postproduction

Government

15

3

Analyst

Commercial

10

4

Senior manager (mgr.)

Government

30

5

Support chief

Government

30

6

Specialist

Government

25

7

Senior analyst

Commercial

9

8

Division chief

Government

6

9

Item mgr.

Government

3

10

Senior mgr.

Government

20

11

MRO mgr.

Government

25

12

Logistics mgr.

Government

30

13

MRO mgr.

Commercial

10

14

MRO mgr.

Commercial

5

15

MRO mgr.

Commercial

10

16

Specialist

Government

20

17

Chief

Government

25

See all solutions

Recommended explanations on Math Textbooks

View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.