STSCI 2150 Prelim 1
Oct 1, 2013
1. What is volunteer bias? Give an example. 
People who volunteer for a study are not representative of the general population. If a study
uses only volunteers, the results will be biased because a non-represen
The Analysis of Biological Data - Whitlock and Schluter
Solutions to practice problems
1. (a) Ordinal (b) Nominal (c) Nominal (d) Ordinal
2. (a) Observational (cats were observed to fall a given number of storiesthe researchers did not
a. The average Titanic passenger age is 31.2 years.
b. The youngest age of a Titanic passenger is 0.1667 years (0.17 years)
c. The oldest age of a passenger is 71 years.
d. There are 633 passengers in the data s
a. 188.0643 mg is the mean
b. 95% CI: (167.52, 208.60)
Its not really predictable based on the spread of the histogram. It seems as though 160180mg is the most frequent, but there are values for mg amounts ranging from 140-260.
b. The equation Y =.25+.95X. Or, in more general terms, Offspring length= .
c. Null Hypothesis: The slope of the regression of offspring telomere length by
father telomere length is zero
a. n=5, sd=5.
d. The estimate for n=5 was 2.24. N=16, the estimate was 1.28. N=25, the
esitamte was 1. They are close.
Null Hypothesis: Honeybees do not distingu
Lab 10: Comparing Two Groups
Due by Wednesday November 2 at 11:59pm
Your solutions to the problems below should be put into a lab report. You should
work on this lab during your lab section, so that you can get help if needed from the
a. Mosaic plot on the left has separate colors identifying the Survived group
and the Dead group.
-Mosaic plot on the left has a numbered y-axis that notes frequency.
-Mosaic plot of the right has large