Homework 9 Solutions
1. George has an average bowling score of 180 and bowls in an amateur league where the
average for all bowlers is 150 and the standard deviation is 20. Bill has an average bowling
score of 190 and b
Heights of adults, ages 18-24
mean: 70.0 inches
standard deviation: 2.8 inches
68% of men are between 67.2 and 72.8 inches
95% of men are between 64.4 and 75.6 inches
99.7% of men are between 61.6 an
Scatterplots & Correlation
So far, weve only examined the distribution of a
single variable. We can look at some sort of
graphical display or numerical summary.
Often times, however, we would like to see
Thinking About Chance
THOUGHT QUESTION 1
Here are two very different probability questions:
If you roll a 6-sided die and do it fairly, what is the
probability that it will land with 3 showing?
What is the probability that in your lifetime you
What is a Test of Significance?
On November 6th, 2008, the Kentucky Kernel
In spring 2004, 28% of UK students smoked. In
fall 2007, a survey of 469 students showed 89
Lets calculate a 95% confidence inte
What is a Test of Significance?
State the null and alternative hypotheses in the
A Gallup Poll found that 40% of American adults
say they attended religious services last week.
We suspect that the true
Homework 1 Solutions
1. An opinion poll contacts 1000 randomly selected adults from the U.S. and asks them, Please
tell if you have bought a lottery ticket in the last 12 months.
a. What is the population in this observa
Solutions for Suggested Problems from Chapter 15
1. The least-squares regression line for predicting SAT math score from percentage taking is
SAT score = (-97.0*proportion taking) + 575.3
a. When describing the relationship between these two variables, ho
Homework 10 Solutions
1. For a biology project, you measure the length (centimeters) and weight (grams) of 12
a. Explain why you expect the correlation between length and weight to be positive.
Homework 8 Solutions
1. Yolanda would like to go to a prestigious graduate school of the arts. The following data represent
the dance audition scores of Yolandas group.
Displaying Distributions with Numbers
Describing the center and spread of a distribution
using words is inadequate. Instead, we want to
describe these topics using numbers.
Describing Distributions with Numbers
As we discussed in the previous chapter, we
always describe a distribution with some sort of
graphical display (e.g. histogram, stemplot).
Describing the center and spread of a di
STATISTICS A FORCE ON HUMAN JUDGMENT
SUMMER I 2011
(Tentative, Tentative, Tentative, )
Office: 859D POT
Email: [email protected]
Office Hours: By Appointment
Where Do Data Come From?
TALKING ABOUT DATA
Individuals are the objects described by a set of
A variable is any characteristic of an individual.
Variables can take different values for different
Sample Surveys in the Real World
HOW SAMPLING CAN GO WRONG
Statistical theory is a nice thing to talk about,
but since humans are involved, chances are good
that our samples will not always be executed
We made confidence statements t
Experiments, Good and Bad
THOUGHT QUESTION 1
In research to determine the relationship
between two conditions (activities, traits, etc.),
one of them is often defined as the explanatory
(independent) variable and the other as the
outcome or resp
Experiments in the Real World
EQUAL TREATMENT FOR ALL SUBJECTS
The underlying assumption of randomized
comparative experiments is that all subjects are
handled equally in every respect except with
regard to the treatments being compared.
Graphs, Good and Bad
The first part of this course dealt with the
production of data, through random sampling
and randomized comparative experiments.
This particular unit focuses on good ways to
summarize and organize data.
Displaying Distributions with Graphs
Pie charts and bar graphs display the
distribution of categorical variables.
How can we present the distribution of a
Quantitative variables usually take too many
Homework 6 Solutions
1. A survey of 1000 college freshmen in 2001 asked what field they planned to study. The
results: 126 said arts and humanities, 166 said business, 101 said education, 186 said
engineering and scienc
Solutions for Suggested Problems from Chapter 6
1. Exercise 6.4 from book (page 115).
The ratings were not double-blind because the researcher knew which subjects
received the capsaicin and which received the placebo. If the researcher beli
Homework 5 Solutions
1. Although the law doesnt require it, we decide to subject Dr. Moores Indiana Extract to a
clinical trial. We hope to show that the extract reduces pain from arthritis. One-hundred
child mortality vs co2
Child mortality (0-5 year
old dying per 1,000
2. there is no association between the co2 emission and mortality child rate,
there can be low cod but in high hundreds co2
3. the a
1. Yes because as the DTP coverage increases the autism line drastically
1. no there is no clear correlation between heart failure and whole grain
because the study does not tell us what kind of physical shape these men are in