NAME: _______________________________ DATE: _______________ SCORE: _____/100
MATH5500: STATISTICAL METHODS
FOR ANALYZING DATA SAS PROJECT – FALL 2021
Directions: Please complete each problem in SAS. For each problem, you will be
Ø Submit your SAS code.
Ø Submit the results screen for your code.
Ø Answer any questions posed to you.
1. The article “Daily Weigh-Ins Can Help You Keep Off Lost Pounds, Experts Say,”
(Associated Press, October 17, 2005) describes an experiment in which 291 people who
had lost at least 10% of their body weight in a medical weight-loss program were
assigned at random to one of three groups for follow-up. One group met monthly in
person, one group met monthly in an online chat room, and one group received a monthly
newsletter by mail. After 18 months, participants in each group were classified
according to whether or not they had regained more than 5 pounds, according to the table
a. What is the expected number of participants who met in-person and regained 5
pounds or less?
b. The researchers wanted to determine whether the type of follow-up group is
associated with the amount of weight regained. Write the appropriate null and
c. What are the degrees of freedom for the test?
d. If using � = 0.01, what is the critical value of the test, according to the �! table?
e. Report the test statistic and �-value for the test. What conclusion can you draw?
Regained � lbs or Less Regained More than � lbs
In-Person 52 45
Online 44 53
Newsletter 27 70
2. The article “Genetic Tweak Turns Promiscuous Animals into Loyal Mates” (Los Angeles
Times, June 17, 2004) summarizes a research study that appeared in the June 2004 issue
of Nature. In this study, 11 male meadow voles that had a single gene introduced into a
specific part of the brain were compared to 20 male meadow voles that did not undergo
the genetic manipulation. All of the voles were paired with a receptive female partner for
24-hours. At the end of the 24-hour period, the male was placed in a situation where he
could either choose the partner from the previous 24-hours or a different female. The
percentage of the time that the male spent with his previous partner during a 3-hour time
period was recorded and the data is presented below.
a. Using � = 0.05, is there evidence to suggest that the population variances for the
genetically modified group versus the unmodified group are equal? Report the
test statistic and the �-value?
b. Based on the results of Part a, which will be more appropriate for comparing the
mean percentage of the 3-hour period spent with the first female partner, the
pooled estimate of variance or the Satterthwaite estimate of the degrees of
c. Using � = 0.05, do the genetically modified voles spend a different percentage of
a 3-hour period with the first female partner when compared to the unmodified
voles? Report the appropriate test statistic and �-value.
Genetically Altered: 59, 62, 73, 80, 84, 85, 89, 92, 92, 93, 100
Not Genetically Altered: 2, 5, 13, 28, 34, 40, 48, 50, 51, 54, 60, 67, 70, 76, 81, 84, 85, 92, 97,
3. Northern flying squirrels eat lichen and fungi, which makes for a relatively low-quality
diet. The authors of the paper “Nutritional Value and Diet Preference of Arboreal
Lichens and Hypogeous Fungi for Small Mammals in the Rocky Mountains” (Canadian
Journal of Zoology : 851-862) measured nitrogen intake (�, in grams) and nitrogen
retention (�, in grams) in six flying squirrels that were fed the fungus Rhizopogon. Data
from a graph in the paper is presented below.
a. Determine the equation of the linear regression model for this data.
b. What is the standard error of the slope?
c. Is there a significant linear relationship in nitrogen retention vs. nitrogen intake
for all Northern flying squirrels? Use � = 0.05. Report the test statistic and �-
Nitrogen Intake (grams) Nitrogen Retention (grams)
4. The effect of caffeine levels on performing a simple finger tapping task was investigated
in a double-blind study. Thirty male college students were trained in finger tapping and
randomly assigned to receive three different doses of caffeine (0, 100, or 200 mg) with
10 students per dose group. Two hours following the caffeine treatment, students were
asked to finger tap and the number of taps per minute were counted. The data is
a. Present the ANOVA table for the data.
b. Using � = 0.10, is there evidence to suggest that the mean number of finger taps
per minute is the same across all treatment groups? Report the test statistic and �-
� mg ��� mg ��� mg
242 248 246
245 246 248
244 245 250
248 247 252
247 248 248
248 250 250
242 247 246
244 246 248
246 243 245
242 244 250
5. Three different washing solutions are being compared to study their effectiveness in
slowing bacteria growth in five-gallon milk containers. The analysis is done in a
laboratory, and only three trials can be run on any day. Because days could represent a
potential source of variability, the experimenter decides to use a randomized block
design. Observations are taken for four days, and the data are shown below.
a. Present the ANOVA table for the data.
b. Using � = 0.05, determine whether the different types of washing solutions are
equally effective in slowing bacterial growth in the five-gallon milk containers.
Report the test statistic and �-value.
Days 1 2 3
1 13 16 5
2 22 24 4
3 18 17 1
4 39 44 22