Week 1 Assignment
1. Determine which of the following statements is descriptive in nature and which is inferential. Refer to the data below in How Old is My Fish?
How Old is My Fish  
Average age by length of largemouth bass in new York State  
Length 
8 
9 
10 
11 
12 
13 
14 
Age 
2 
3 
3 
4 
4 
5 
5 
a. All 9inch largemouth bass in New York State are an average of 3 years old.
b. Of the largemouth bass used in the sample to make up th NYS DEC Freshwater Fishing Guide, the average age of 9inch largemouth bass was 3 years.
In your answer also describe and explain the difference between descriptive statistics and inferential statistics.
Question 2
2. Since 1981, Fortune magazine has been tracking what they judge to be the “best 100 companies to work for.” The companies must be at least ten years old and employ no less than 500 people. Below are the top 25 from the list compiled in 1998, together with each company’s percentage of females, percentage of job growth over a 2 year span, and number of hours of professional training required each year by the employer.
Company Name  Women (%)  Job Growth (%)  Training (hr/yr) 
Southwest Airlines  55  26  15 
Kingston Technology  48  54  100 
SAS Institute  53  34  32 
FELPro  36  10  60 
TDIndustries  10  31  40 
MBNA  58  48  48 
W.L.Gore  43  26  27 
Microsoft  29  22  8 
Merck  52  24  40 
HewlettPackard  37  10  0 
Synovus Financial  65  23  13 
Goldman Sachs  40  13  20 
MOOG  19  17  25 
DeLoitte&Touche  45  23  70 
Corning  38  9  80 
Wegmans Food Products  54  3  30 
HarleyDavidson  22  15  50 
Federal Express  32  11  40 
Proctor & Gamble  40  1  25 
Peoplesoft  44  122  0 
First Tennessee Bank  70  1  60 
J.M. Smucker  48  1  24 
Granite Rock  17  29  43 
Petagonia  52  5  62 
Cisco Systems  25  189  80 
a. Find the mean, range, variance, and standard deviation for each of the three variables shown in the list. Present your results in a table.
b. Using your results from (a), compare the distributions for job growth percentage and percentage of women employed. What can you conclude?
Grading Criteria Assignments  Maximum Points 
Meets or exceeds established assignment criteria  40 
Demonstrates an understanding of lesson concepts  20 
Clearly present wellreasoned ideas and concepts  30 
Mechanics, punctuation, sentence structure, spelling that affects clarity, and citation of sources as needed  10 
Total  100 
Week2 Assignment
Assignment Week 2
Question 1
1. Baseball stadiums vary in age, style, size, and in many other ways. Fans might think of the size of the stadium in terms of the number of seats; while the player might measure the size of the stadium by the distance from the homeplate to the centerfield fence. Note: CF = distance from homeplate to centerfield fence.
Using the Excell addin construct your scatter diagram with the data set provide below.
Seats  CF  
38805  420  
41118  400  
56000  400  
45030  400  
34077  400  
40793  400  
56144  408  
50516  400  
40615  400  
48190  406  
36331  434  
43405  405  
48911  400  
50449  415  
50091  400  
43772  404  
49033  407  
47447  405  
40120  422  
41503  404  
40950  435  
38496  400  
41900  400  
42271  404  
43647  401  
42600  396  
46200  400  
41222  403  
52355  408  
45000  408 
Is there a relationship between these two measurements for the “size” of the 30 Major League Baseball stadiums?
a. Before you run your scatter diagram answer the following: What do you think you will find? Bigger fields have more seats? Smaller fields have more seats? No relationship exists between field size and number of seats? A strong relationship exists between field size and number of seats? Explain.
b. Construct a scatter diagram and include it in your answer.
c. Describe what the scatter diagram tells you, including a reaction to your answer in (a).
Question 2
2. Place a pair of dice in a cup, shake and dump them out. Observe the sum of dots. Record 2, 3, 4, _ , 12. Repeat the process 25 times. Using your results, find the relative frequency for each of the values: 2, 3, 4, 5, _ , 12.
Grading Criteria Assignments  Maximum Points 
Meets or exceeds established assignment criteria  40 
Demonstrates an understanding of lesson concepts  20 
Clearly present wellreasoned ideas and concepts  30 
Mechanics, punctuation, sentence structure, spelling that affects clarity, and citation of sources as needed  10 
Total  100 
Assignment Week 3
Question 1
If you could stop time and live forever in good health, what age would you pick? Answers to this question were reported in a USA Today Snapshot. The average ideal age for each age group is listed in the following table; the average ideal age for all adults was found to be 41. Interestingly, those younger than 30 years want to be older, whereas those older than 30 years want to be younger.
Age Group  Ideal Age 
18 – 24  27 
25 – 29  31 
30 – 39  37 
40 – 49  40 
50 – 64  44 
65 +  59 
Age is used as a variable twice in this application.
 The age of the person being interviewed is not the random variable in this situation. Explain why and describe how “age” is used with regard to age group.
 What is the random variable involved in this study? Describe its role in this situation.
 Is the random variable discrete or continuous?
Question 2
Find the area under the normal curve that lies to the left of the following zvalues.
 Z=1.30
 Z=3.20
 Z=2.56
 Z=0.64
Grading Criteria Assignments  Maximum Points 
Meets or exceeds established assignment criteria  40 
Demonstrates an understanding of lesson concepts  20 
Clearly present wellreasoned ideas and concepts  30 
Mechanics, punctuation, sentence structure, spelling that affects clarity, and citation of sources as needed  10 
Total  100 
Assignment Week 5
Question 1
Using the telephone numbers listed in your local directory as your population, randomly obtain 20 samples of size 3. From each telephone number identified as a source, take the fourth, fifth, and sixth digits.
 Calculate the mean of the 20 samples
 Draw a histogram showing the 20 sample means. (Use classes 0.5 to 0.5, 0.5 to 1.5, 1.5 to 2.5 and so on).
 Describe the distribution of the xbars that you see in part b (shape of distribution, center, and the amount of dispersion).
 Draw 20 more samples and add the 20 new xbars to the histogram in part b. Describe the distribution that seems to be developing.
Use the empirical rule to test for normality. See the sampling distribution of sample means and the central limit theorem develop from your own data!
Question 2
Consider a population with μ = 43 and σ = 5.2.
 Calculate the zscore for an x̅ of 46.5 from a sample of size 35.
 Could this zscore be used in calculating probabilities using Table 3 in Appendix B? Why or why not?
Question 3
State the null and alternative hypotheses for each of the following:
 You want to show an increase in buying and selling of singlefamily homes this year when compared with last year’s rate.
 You are testing a new recipe for “lowfat” cheesecake and expect to find that its taste is not as good as traditional cheesecake.
 You are trying to show that music lessons have a positive effect on a child’s selfesteem.
 You are investigating the relationship between a person’s gender and the automobile he or she drives—specifically you want to show that more males than females drive trucktype vehicles.
Grading Criteria Assignments  Maximum Points 
Meets or exceeds established assignment criteria  40 
Demonstrates an understanding of lesson concepts  20 
Clearly present wellreasoned ideas and concepts  30 
Mechanics, punctuation, sentence structure, spelling that affects clarity, and citation of sources as needed  10 
Total  100 
Assignment Week 6
Question 1
Based on a survey of 1,000 adults by Greenfield Online and reported in a May 2009 USA Today Snapshot, adults 24 years of age and under spend a weekly average of $35 on fast food. If 200 of the adults surveyed were in the age category of 24 and under and they provided a standard deviation of $14.50, construct a 95% confidence interval for the weekly average expenditure on fast food for adults 24 years of age and under. Assume fast food weekly expenditures are normally distributed.
Question 2
An experiment was designed to estimate the mean difference in weight gain for pigs fed ration A as compared with those fed ration B. Eight pairs of pigs were used. The pigs within each pair were littermates. The rations were assigned at random to the two animals within each pair. The gains (in pounds) after 45 days are shown below:
RationA  RationB 
65 
58 
37 
39 
40 
31 
47 
45 
49 
47 
65 
55 
53 
59 
59 
51 
Assuming weight gain is normal, find the 95% confidence interval estimate for the mean of the differences μ_{d} where d= ration A – ration B.
Assignment Week 7
Question 1
To compare commuting times in various locations, independent random samples were obtained from the six cities presented in the “Longest Commute to Work” graphic on page 255 in your textbook. The samples were from workers who commute to work during the 8:00 a.m. rush hour. Oneway Travel to Work in Minutes
Atlanta 
Boston 
Dallas 
Philadelphia 
Seattle 
St. Louis 
29 
18 
42 
29 
30 
15 
21 
37 
25 
20 
23 
24 
20 
27 
26 
33 
31 
42 
15 
25 
32 
37 
39 
23 
37 
32 
20 
42 
14 
33 
26 
34 
26 


18 

48 
35 


 Construct a graphic representation of the data using six sidebyside dotplots.
 Visually estimate the mean commute time for each city and locate it with an X.
 Does it appear that different cities have different effects on the average amount of time spent by workers who commute to work during the 8:00 a.m. rush hour? Explain.
 Does it visually appear that different cities have different effects on the variation in the amount of time spent by workers who commute to work during the 8:00 a.m. rush hour? Explain.
Part 2
 Calculate the mean commute time for each city depicted.
 Does there seem to be a difference among the mean oneway commute times for these six cities?
 Calculate the standard deviation for each city’s commute time.
 Does there seem to be a difference among the standard deviations between the oneway commute times for these six cities?
Part 3
 Construct the 95% confidence interval for the mean commute time for Atlanta and Boston.
 Based on the confidence intervals found does it appear that the mean commute time is the same or different for these two cities (Atlanta and Boston). Explain
 Construct the 95% confidence interval for the mean commute time for Dallas.
 Based on the confidence intervals found in (Atlanta and Boston) and Dallas does it appear that the mean commute time is the same or different for Boston and Dallas? Explain.
 Based on the confidence levels found in (Atlanta and Boston) and (Dallas) does it appear that the mean commute time is the same or different for the set of three cities, Atlanta, Boston, and Dallas? Explain
 How does your confidence intervals compare to the intervals given for Atlanta, Boston, and Dallas in “Longest Commute to Work” on page 255?
Question 2
Interstate 90 is the longest of the eastwest U.S. interstate highways with its 3,112 miles stretching from Boston, MA at I93 on the eastern end to Seattle WA at the Kingdome on the western end. It travels across 13 northern states; the number of miles and number of intersections in each of those states is listed below.
State  No. of Inter  Miles 
WA  57  298 
ID  15  73 
MT  83  558 
WY  23  207 
SD  61  412 
MN  52  275 
WI  40  188 
IL  19  103 
IN  21  157 
OH  40  244 
PA  14  47 
NY  48  391 
MA  18  159 
 Construct a scatter diagram of the data.
 Find the equation for the line of best fit using x= miles and y=intersections.
 Using the equation found in part (b), estimate the average number of intersections per mile along I90.
 Find a 95% confidence interval for β_{1}.
 Explain the meaning of the interval found in part d.