Stats 2400, Technology Team Project                       Names _________________________

R. Sinn, Spring 2008                                                     

                                                                                                            _________________________

 

Project Tasks

·                     Format: Complete the 8 problems below and combine the answers into a single Excel file with a separate worksheet page for each problem.  Answer text questions in Excel in cells near your graphics and data. For TI-83/84 questions, enter responses as text into the proper spreadsheet page. For StatsPortal questions, past graphics into excel and type text responses.

·                     Graphics: You may use bar graphs or histograms, but there are bonus points for figuring out how to make histograms (or bar graphs with zero “gap width”). The graphs will all be made by selecting the appropriate columns of data and using the chart wizard.

·                     Numerics: Here are some formulas you will use (data list is selected by using the mouse):

      •  =Average(datalist)
      • =Median(datalist)
      • =StDev(datalist)
      • =Percentile(datalist,percentile)
      • =Countif(datalist, criteria)

·                     Turn In: Team leader should email completed work to Dr. Sinn by the due data.

 

Directions, Problems 1 - 4: Enter and analyze the following data sets in Excel.  You should complete all of the following steps.

a.             Add a column for a relative frequency table.

b.            Make a relative frequency bar graph and/or histogram.

c.             Discuss the shape of the data set.  Is it normal?  Is it skewed?  If skewed, left or right?

d.            For #3 only, provide a standard data table + median.

e.             Do you believe the mean is greater than, approximately equal to or less than the median?

f.             Based upon part (e) discuss whether the data set is likely to have outliers, and why you think so.

 

1.             The table below gives the frequencies of birth weights for nearly 4 million infants born in the United States in 1986.

 

Birth Weight (grams)

Number of Newborns

0 – 499

4,843

500 – 999

17,487

1000 – 1499

23,139

1500 – 1999

49,112

2000 – 2499

160,919

2500 – 2999

597,738

3000 – 3499

1,376,008

3500 – 3999

1,106,634

4000 – 4499

344,390

4500 – 4999

62,769

5000 – 5500

8,236

 

2.             Over 700 bus drivers employed by public corporations participated in a survey to determine the number of traffic accidents each bus driver was involved in during a 4 year period.  The results are given below:

 

Number of Accidents

0

1

2

3

4

5

6

7

8

9

10

11

Bus Drivers

117

157

158

115

78

44

21

7

6

1

3

1

 

3.             Promiscuous Raccoons: Researchers monitored the courtship of mating raccoons in southern Texas during 3 mating seasons in an effort to describe mating behavior.  Twenty-nine female raccoons were observed, and the number of male partners during the time the female was accepting partners (generally 1 – 4 days per year) was recorded for each female.  The resulting data were as follows:

 

1

2

3

1

1

4

2

4

1

1

1

3

1

1

1

1

2

2

1

1

4

1

1

2

1

1

1

1

3

 

Bonus: use “countif” to have Excel make frequency table.

 

4.             Criminology researchers reported the number of prior convictions for nearly 300 adult males arrested for felony offenses:

 

Prior Convictions

0

1

2

3

4

5

6

7

8

9

10

11

Frequency

0

16

27

37

46

36

40

31

27

13

8

2

 

 

Directions, Problems 5 - 6: Analyze the following data sets with a graphing calculator.  You should complete all of the following steps.

 

a.             Use your graphing calculator to make a box plot of the data.  Are there any outliers?  If so, which data points are the outliers?

b.            Use your graphing calculator to make a histogram. Do the data appear normal? Skewed? Left or right?

c.             Check for outliers using the z-score method ( | z | > 2 ).

d.            Calculate and report a standard data table + median.

e.             Is the mean greater than, approximately equal to or less than the median? Explain your reasoning.

 

5.             The Connecticut Agricultural Experiment Station conducted a study of the calorie content of the different types of beer.  The calorie contents (calories per 100 ml) for 26 brands of light beer are given below (data from brewery.org):

 

29

28

33

31

30

33

30

28

27

41

39

31

29

23

32

31

32

19

40

22

34

31

42

35

29

43

 

6.             Researchers conduct a household survey in a certain community asking, among other things, “number of rooms per dwelling unit.”  The following table shows the results.

 

3

2

4

4

1

6

3

6

6

6

7

6

5

7

5

2

7

5

4

6

8

4

5

7

4

3

6

6

4

3

6

5

5

6

7

6

5

5

2

5

8

6

6

3

7

7

7

5

6

1

5

6

5

4

3

4

3

6

5

4

 

 

Directions, Problems 7 – 8: Enter and analyze the following data sets using StatsPortal’s CrunchIt, a similar piece of technology as the TI graphing calculator but with all the data sets from our textbook preloaded. You should complete all of the following steps.

 

7.             Open StatsPortal, browse to Chapter 3 exercises, problem 3.29. The question is about IQ scores for 7th grade girls. Click on the “CrunchIt” icon to the left. You may need to download a plug-in for your browser. If have current versions of Java and the proper plug-ins, then fter 5 – 10 seconds, depending upon hardware and your internet connection, you should see the data set appear in CrunchIt, a program that looks very similar to a spreadsheet application like Excel.

 

a.     Use the “Data” menu, “Sort Columns” option to sort the data. What are the minimum and maximum values?

b.    Use the “Stat” menu, “Summary Stats” option. Record a standard data table and the five number summary. Bonus points for learning to copy-paste your results as a table into Excel.

c.     Use the “Graph” menu, “Histogram” option. Let CrunchIt use it’s default settings for “bin width” and “start bin.” Use “Options” tab on the output screen to “copy-paste” the graphics into Excel.

d.    Use the “Graph” menu, “Box Plot” option. As you hit the “next” button, you will have the option to select “identify outliers with fences” as a checkbox. Do so. Past the graph into Excel, and state if there are outliers in the data set.

e.     Based on steps a – d above, do the data appear normal? Skewed? Left or right? Explain.

 

8.             In CrunchIt, using the hyperlinks in the black frame on the left, browse to “Chapter 4” exercises, problem 22. Here is the text from the eBook explaining the data: “What is the relationship between returns from buying Treasury bills and returns from buying common stocks? To buy a Treasury bill is to make a short-term loan to the U.S. government. This is much less risky than buying stock in a company, so (on the average) the returns on Treasury bills are lower than the return on stocks.”

a.     Use the “Stat” menu, “Summary Stats” option. Record a standard data table and the five number summary for both t-bill data and stock data.

b.    Use the “Graph” menu, “Box Plot” option. Use “identify outliers with fences” checkbox, and plot both graphs on “same x-axis.” Past the graph into Excel, and state if there are outliers in the data sets.

c.     Use the “Graph” menu, “Histogram” option. Let CrunchIt use it’s default settings for “bin width” and “start bin.” Bonus for using “overlay” feature to display normal distribution curve in red on the histogram. Use “Options” tab on the output screen to “copy-paste” the graphics into Excel.

d.    Based on steps a – c above, compare and contrast the two data sets above. Are they skewed? In the same direction or opposite directions? Do they have outliers?

e.     Which type of investment was “better”? Explain your reasoning in 1 – 2 complete sentences.