ph 142
KEY
problem set 7
15 points
Part 1. hypothesis test about a mean
9 points
Vitamin C loss in wheat soy blend
These are the same data as we used in problem set 6 to calculate a confidence interval.
The assumptions for using t distributions for hypoth
ph 142
preparing for quiz 2
The quiz is in section on Friday February 26
What does the quiz cover?
normal probability distributions N(,)
know that every distribution in the normal family of distributions
is completely characterized by 2 parameters:
1. the
ph 142 Workshop Problems partial key
probability and random variables
Part 1.
Suppose the probability of the school of public health softball team winning an intramural game is
.40, no matter which team they are playing, and that their game results are in
ph 142
problem set 4
10 points
random variables
winnings at heads and tails
Jos and Juanita are playing a coin-tossing game.
They toss 4 fair coins. P( head ) = 1 / 2 and P( tail ) = 1 / 2 for every toss.
The coins are independent.
Jos wins a dollar from
ph 142
probability and statistics in biology and public health
spring 2016
descriptive statistics
probability
sampling distributions
confidence intervals and tests for means and proportions
comparing the means of 2 populations and proportions from 2 popul
two-sample practice problems for means
adapted from Baldi and Moore
exercise 18.28
page 458
testosterone and obesity in adolescent males
Obesity in adult males is associated with lower levels of sex hormone. Example 17.2 described a study
investigating a
ph 142
section activities Wednesday Apr 26 and Thursday Apr 27
partial key
A study was carried out to explore the relationship between drivers ages and the maximum
distance away at which they could read road signs. (Call this "legibility distance.")
Assum
ph 142
practice problems for hypothesis tests one sample problems
partial solutions
for a population mean
In these problems, we don't have the raw data.
Look at the sample size and the information given to be sure it's reasonable to use the t
distribution
two-sample practice problems for ph 142 final
partial key
adapted from Baldi and Moore
exercise 18.28
page 458
testosterone and obesity in adolescent males
Obesity in adult males is associated with lower levels of sex hormone. Example 17.2 described a stu
ph 142
fall 2016
quiz 3
for practice for the final
You may use the salmon summary handout.
You will need a simple scientific calculator. You may not use a cell phone calculator.
Show all work on these sheets; you may use the backs of the pages as needed.
ph 142
fall 2016
quiz 4
for practicing for the final
2
You may use the buff-colored two-sample summary sheet and the blue test summary .
You will need a simple scientific calculator. You may not use a cell phone calculator.
Show all work on these sheets.
ph 142
section activities Wednesday Apr 26 and Thursday Apr 27
A study was carried out to explore the relationship between drivers ages and the maximum
distance away at which they could read road signs. (Call this "legibility distance.")
Assume that the d
ph 142
KEY
problem set 7
15 points
Part 1. hypothesis test about a mean
9 points
Vitamin C loss in wheat soy blend
These are the same data as we used in problem set 6 to calculate a confidence interval.
The assumptions for using t distributions for hypoth
ph 142
problem set 11
10 points
Its a really good idea to always include your plots with your solutions.
The directions do say "Copy and paste your graphs and the Stata results into your report."
We will take off 1 point overall if you did not do this for
ph 142
spring 2016
quiz 3
KEY
Part 1. (20 points) Researchers studied macaque monkeys to see how their brains responded to
pure tones and to actual macaque calls. In a matched pairs study, 37 macaques were studied.
Their neural activity in response to eac
ph 142
midterm key
spring 2016
Part 1. conditional probability reasoning
8 points
In an investigation of possible factors associated with breast cancer in women, a large
international case-control study was carried out. A womans age at the birth of her fi
using the fitted values from a regression
to estimate the mean outcome for the population with a given X
and to predict the outcome for an individual with a given X;
confidence intervals for estimation and prediction
The reason these questions can be tric
ph 142
problem set 6
partial key
10 points
confidence intervals for a mean
Vitamin C loss in wheat soy blend
The units on the vitamin C measurements are milligrams of vitamin C per 100 grams of WSB.
. gen loss = factory Haiti
. summ loss, detail
vitamin C
ph 142
practice problems for hypothesis tests one sample problems
for a population mean
In these problems, we don't have the raw data.
Look at the sample size and the information given to be sure it's reasonable to use the t
distribution for confidence in
ph 142
quiz 2
fall 2016
for practice for the final
You may use the salmon summary handout from class.
You will need a simple scientific calculator. You may not use a cell phone calculator.
A copy of the t table from Baldi and Moore is available.
Show all
2
ph 142 Workshop Problems
tests
brief answer key
I. fathers and sons' occupations
here is a table of the expected counts under the null hypothesis:
doctors
same occup
34.3
different occup
bankers
165.7
2
teachers
lawyers
25.7
30.9
17.1
124.3
149.1
82.9
t
ph 142
preparation for midterm
The exam will begin at 8:00 am sharp.
You may bring one 8 by 11 sheet with formulas, the probability summary,
and the counting rules summary.
You will need a calculator. Cell phone calculators may not be used during the exam
University of California, Berkeley
School of Public Health
On-Campus/Online Professional MPH Degree Program
PH W142: INTRODUCTION TO PROBABILITY AND STATISTICS
Fall 2011
Instructor: Maureen Lahiff, PhD
307 Haviland Hall, [email protected]
Course format:
ph 142 Workshop Problems
two-sample problems
brief answer key
I. FEV
difference in averages
.3595
est std error of difference
0.1638
test statistic
2.19
34 df
P value for two-tailed alt hyp 0.035
II. binge drinking
estimated proportions
men
.227
women .
ph 142 Workshop Problems
more hypothesis tests
brief answer key
I. tests for proportions
13. "sometimes I copy information from the internet into my papers without reporting the
source."
under the null hypothesis, the standard error for the sample proport
ph 142
2
Workshop Problems
This week features both 2
2
tests for association and a
tests
goodness of fit test .
Part I.
A research organization, interested in testing whether the proportions of sons taking up the
occupations of their fathers are equal fo
ph 142 Workshop Problems
confidence intervals,
hypothesis tests, and power
brief answer key
I. Confidence intervals for a population mean
assuming that the populationvariance is known.
SAT math scores have a normal distribution with a standard deviation o
ph 142 Workshop Problems
confidence intervals,
hypothesis tests, and power
There's a lot of material here; we can finish it next week.
The focus of this week's problems is
confidence intervals for population means
confidence intervals for population propo
ph 142 Workshop Problems
more hypothesis tests
The focus of this week's problems continues to be hypothesis tests:
one-sample proportion problems
paired t tests,
two independent sample t tests to compare the means of two populations
I. tests for a proport
using
tables, the SurfStat
The terms in the
applet, and Stata's chi2tail function
statistic that compare the observed and expected counts will be small if
the observed counts are close to the expected counts under the null hypothesis. The
terms
are always
ph 142
spring 2016
quiz 4
KEY
Part I (11 points)
The units on the exposure are milligram years per cubic meter (of air) abbreviated mg*y/m 3 .
The data for total dust exposure are:
n
average
standard deviation
drill and blast workers
115
18.0
7.8
outdoor
ph 142
spring 2016
quiz 5
KEY
A study was carried out to explore the relationship between drivers ages and the maximum
distance away at which they could read road signs. (Call this "legibility distance.")
Assume that the drivers were tested under the same
ph 142
spring 2016
quiz 2
KEY
The diastolic blood pressures of healthy young women between the ages of 18 and 30 in the US
have a distribution that is approximately normal with a mean of 77.0 mm Hg and a standard
deviation 12 mm Hg. [Diastolic is the seco
ph 142
key
problem set 8
confidence intervals and hypothesis tests about a proportion
20 points
19.34 coffee tasting
11 points
The null hypothesis is that people really cant tell freshly-brewed coffee from instant.
If we make them pick one that they like