Stat 104 – Homework 3
Due Thursday September 15, 2011
Reading:
September 6 – September 15
September 20 – September 27
Chapter 3
Chapter 4
Assignment:
1. Complete the following problems from the text: 3.1, 3.5, 3.11, and 3.16.
2. One definition of binge drinking is consuming 4 or more alcoholic drinks in a 2hour period for females or 5 or more alcoholic drinks in a 2-hour period for males.
In fall 2010 Stat 104 students completed a questionnaire at the beginning of the
semester. Of the 257 Stat 104 students who completed the questionnaire, 160
students indicated that they drank alcohol the previous weekend. Using the
definition above, 93 participated in binge drinking. Below is a summary of the
drinking status and gender of the 257 students who completed the questionnaire.
Female
Male
Total
Did not
drink
59
38
97
Drinking status
Drank
Binged
43
24
67
21
72
93
Total
123
134
257
a) Identify the explanatory and response variables.
b) Compute row percentages, conditional proportions for the various drinking
status categories for females and males.
c) Below is a mosaic plot depicting the percentages calculated in b). Use the
percentages from b) and the mosaic plot to compare females to males in terms
of their drinking status. Your comparison should be written in complete
sentences and refer specifically to the percentages and the mosaic plot.
Mosaic Plot
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3. The website www.realbeer.com gives calories, carbohydrates and alcohol
content (% by volume) for over 200 beers. A random sample of 10 beers was
selected and the calories and alcohol content (% by volume) of the beers in the
sample are listed below.
Beer Name
Budweiser
Coors
Original
Weinhard’s
Amber Ale
Dundee
Honey Brown
Keystone
Light
Alcohol %
5.0
Calories
143.0
5.0
148.0
5.3
169.0
4.5
150.0
4.2
100.0
Beer Name
Kilarney's
Red Lager
Michelob
Amber Bock
Redhook
ESB
Sierra Nevada
Summerfest
Yuengling
Porter
Alcohol %
5.0
Calories
197.0
5.2
166.0
5.8
179.0
4.9
158.0
4.5
152.5
a) Plot the data. Use Calories as the explanatory variable, x, and Alcohol %
as the response, y. Describe the relationship between Calories and
Alcohol %.
b) Compute the mean and standard deviation for the Alcohol. Round final
answers to 4 decimal places.
c) Compute the mean and standard deviation for the Calories. Round final
answers to 4 decimal places.
d) Using   x  x  y  y   73.8 , compute the correlation between Calories
and Alcohol %. Round final answer to 3 decimal places. Explain in
words what this correlation means.
4. We often read or hear reports about the relationship between diet and health.
Data were collected on the fat intake (grams per day per capita) and the death rate
(number of deaths per 100,000 people) from colon cancer for 30 nations. The
data are available on Blackboard Learn.
a) Use Analyze – Distribution to create graphical displays and numerical
summaries of the death rate data. The histogram should be oriented so that
death rate is along the horizontal axis. The intervals for death rate should go
from 0 to 28 with an increment of 4 and no minor ticks. The histogram
should have a vertical axis with a scale and label. Be sure to attach the JMP
output to your assignment. Use the JMP output to fully describe the
distribution of death rates for the 30 nations. Write your description in
complete sentences and be sure to refer specifically to the graphical and
numerical summaries.
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