Ma 322: Biostatistics
Solutions to Homework Assignment 3
Prof. Wickerhauser
Due Friday, February 12th, 2016
Read Chapter 8, pages 108134 of our text.
1. Every morning, Rosencrantz flips a coin. If it turns up heads, he rises out of bed and rolls two dice
Ma 322: Biostatistics
Solutions to Homework Assignment 4
Prof. Wickerhauser
Due Friday, February 19th, 2016
Read Chapter 9, An Introduction to Bayesian Data Analysis, pages 135159 of our text.
Note: There are many errors in the relevant formulas in our te
Ma 322: Biostatistics
Solutions to Homework Assignment 5
Prof. Wickerhauser
Due Friday, February 26th, 2016
Read Chapter 10, Stochastic Processes and Markov Chains, pages 160184 of our text.
Note: Although our text has no index or table of contents, it is
Ma 322: Biostatistics
Solutions to Homework Assignment 2
Prof. Wickerhauser
Due Friday, February 5th, 2016
Read Chapter 7, pages 80107, of our e-text to review some basic probability density functions and their
properties, concentrating especially on the
Ma 322: Biostatistics
Solutions to Homework Assignment 1
Prof. Wickerhauser
Due Friday, January 29th, 2016
Begin by obtaining access to the R software package, either by downloading a copy onto
your computer or else by finding a computer with a working in
Ma 322: Biostatistics
Homework Assignment 2
Prof. Wickerhauser
Due Friday, February 5th, 2016
Read Chapter 7, pages 80107, of our e-text to review some basic probability density functions and their
properties, concentrating especially on the normal pdf. C
Ma 322: Biostatistics
Homework Assignment 5
Prof. Wickerhauser
Due Friday, February 26th, 2016
Read Chapter 10, Stochastic Processes and Markov Chains, pages 160184 of our text.
Note: Although our text has no index or table of contents, it is easy to loca
Ma 322: Biostatistics
Homework Assignment 4
Prof. Wickerhauser
Due Friday, February 19th, 2016
Read Chapter 9, An Introduction to Bayesian Data Analysis, pages 135159 of our text.
Note: There are many errors in the relevant formulas in our textbook. Use t
Ma 322: Biostatistics
Homework Assignment 1
Prof. Wickerhauser
Due Friday, January 29th, 2016
Begin by obtaining access to the R software package, either by downloading a copy onto your
computer or else by finding a computer with a working installation. A
Ma 322: Biostatistics
Homework Assignment 3
Prof. Wickerhauser
Due Friday, February 12th, 2016
Read Chapter 8, pages 108134 of our text.
1. Every morning, Rosencrantz flips a coin. If it turns up heads, he rises out of bed and rolls two dice to
decide wha
BIOST 510/DPHS 568 Biostatistics in Dentistry Summer 2014
Homework #2 Solutions
1. Compute confidence intervals, one for the mean, one for a proportion
a. Use formula for Confidence Interval for a mean with unknown variance page
83 of course text.
95% CI
DPHS 568/BIOST 510 Biostatistics in Dentistry Summer 2014
Homework #1, Due Friday, July 11, 2014
1. A study evaluated caries progression in schoolchildren from kindergarten to the end
of second grade. The numbers of primary surfaces that progressed to wor
BIOST 510/DPHS 568 Biostatistics in Dentistry Summer 2014
Homework #1 Solutions
1. Data of caries progression of 65 children
a. Figure 1 presents a histogram with bin widths of size 5. I have put the
observations that are at the bin borders (0, 5, 10, etc
Name _ Quiz 3, Biostatistics in Dentistry, Summer 2006
A study was undertaken to investigate whether regular use of a certain food additive could reduce the amount of Mutans Streptococci in dental plaque. The log CFU of Mutans Streptococci was measured in
Name _ Quiz 2, Biostatistics in Dentistry, Summer 2006
1) Suppose that 25% of Dr. B's patients fail to pay their bills on time. Suppose Dr. B wants to calculate the probability that 5 or more of the next 7 unrelated patients will fail to pay their bills o
DPHS 568 Biostatistics in Dentistry, Summer 2014
Homework #3, Due July 23, 2014 (beginning of class)
1. In a trial evaluating orthodontic relapse1, 29 patients were assigned to part-time
retainer wear after debonding. Littles Irregularity Index (LII) was
BIOST 510/DPHS 568 Biostatistics in Dentistry Summer 2014
Homework #2, Due July16, 2014
1. A study evaluated decay prevention strategies and caries progression in
schoolchildren from kindergarten to the end of second grade. The numbers of
primary surfaces
Biostatistics in Dentistry Summer 2008 Homework #3 solutions
1.
a. You could do this problem by trial and error, plugging different values for |0
1| into the power formula presented in the day 9 lecture and on page 95 of the
coursepack. Note that if we p
DPHS 568 Biostatistics in Dentistry Summer 2007
Answers for homework #3
1.
a. sign test two-sided p-value = 0.210. Do not reject null hypothesis of no
change.
b. Wilcoxon signed rank test
c. Sum of negative ranks = 91, sum of positive ranks = 185. Using t
BIOST 510/DPHS 568 Biostatistics in Dentistry Summer 2008
Homework #2, Solutions
1. From Day 1 lecture notes we know the sample statistics:
We dont know , the true population standard deviation, so we need to use s, the sample
standard deviation to estima
DPHS 568, Summer 2007, Homework #2 Solutions
1.
a) The bell-shaped histogram is the probability histogram for the
averages (central limit theorem)
b) The histogram with the two equal-height bars is the contents of
the urn (equal numbers of 1's and 4's)
c)
DPHS 568, Summer 2006, Homework #2 Solutions
1.
a) The bell-shaped histogram is the probability histogram for the averages
(central limit theorem)
b) The histogram with the two equal-height bars is the contents of the urn
(equal numbers of 1's and 4's
c)
Name _
Quiz 1, Biostatistics in Dentistry, Summer 2006
1. Pictured below are two histograms representing the distributions of mean pocket
depth (MPD) in two populations of 50 patients each.
a. Which population appears to have the greater mean MPD? _
b. Wh
DPHS 568 Biostatistics in Dentistry Summer 2013
Answers for homework #6 (optional practice problems)
1.
Urinary Hg by occlusal amalgam surfaces
a. Note that we are only considering the control subjects, so n=8.
b. line of best fit y = -4.471 + 0.610x (y i
DPHS 568 Biostatistics in Dentistry, Summer 2013, Homework #5 Solutions
1. In the setup in problem #1 each independent unit (study participant) contributes data
for one group or the other. Thus, we want to use the independent samples
methodologies. We wil
DPHS 568, Biostatistics in Dentistry, Summer 2013, Homework #4 Solutions
1.
a) If there really is no true effect (the null hypothesis is true), then a
hypothesis test has 5% chance (the significance level, ) of labeling a
difference statistically signific
DPHS 568, Biostatistics in Dentistry, Summer 2013
Homework #3 Solutions
1.
a) Let denote the mean change in mandibullar LII. The null and alternative
hypotheses should be:
H0: =0, vs H1: 0
Compute the t statistic
0.31 0
2.11
0.7929
Since = 0.05, we comp
BIOST 510/DPHS 568 Biostatistics in Dentistry Summer 2013
Homework #2 Solutions
1. Compute confidence intervals, one for the mean, one for a proportion
a. Use formula for Confidence Interval for a mean with unknown variance page
83 of course text.
95% CI