STAT 100, Section 1: Statistical Concepts and Reasoning
Spring 2005
Midterm Exam 3, Monday, Apr. 11
The exam will be
worth 100 points (out of 500 for the whole course).
Students are responsible for all material covered in lectures
since the second midterm
and all material in Chapters 3, 19, 20, and 21 of the textbook.
There are some
practice problems
and answers
available.
PLEASE, TRY THE PROBLEMS BEFORE YOU LOOK AT THE ANSWERS.
Be honest with yourself: Can you answer each question? Could you do
it on an exam? I'm concerned by the number of people who did poorly
on exam #2, even though it was very similar to (and easier than) the
practice problems I had posted beforehand.
Please remember that on the actual exam, a calculator will not
be necessary. However, you may use one if you wish.
The following brief outline of topics from the book is not an exhaustive
list of things you need to know, but it may help you make sure you
have covered the main ideas.
Chapter 3
Difficulties of constructing measures in statistical experiments
Seven important pitfalls in statistical surveys
Open questions
Closed questions
Clarification of the measurement variables
Measurement of non-numerical items, e.g., emotions, attitudes, self-esteem
Types of variables (categorical vs. quantitative, discrete vs. continuous)
The statistical terms validity, reliability, bias, and variability
Chapter 19
Random sampling as a tool to perform inference about the population
Difference between population values and sample estimates
The Rule for Sample Proportions
Conditions under which the Rule for Sample Proportions is valid
Applications of the Rule for Sample Proportions
Use of the Rule for Sample Proportions
The Rule for Sample Means
Conditions under which the Rule for Sample Means is valid
Applications of the Rule for Sample Means
Use of the Rule for Sample Means
Relationship between increasing the sample size
and the width of a confidence interval
Chapter 20
Definition and interpretation of a confidence interval
Examples of confidence intervals reported by the media
Standard deviation of all possible sample proportions
Confidence intervals for a population proportion
95% (and other levels of) confidence
Relationship between the margin of error and the level of confidence
Chapter 21
Calculation of the Standard Error of the Mean (SEM)
Definitions of the population S.D., the sample S.D., and the SEM
Confidence intervals for a population mean
Relationship between the margin of error and the level of confidence
Relationship between the level of confidence, sample size, and width
of the confidence interval
Relationship between the multipliers for 95% confidence interval and
for other levels of confidence
Standard error of difference of sample means: The square root of
[(SEM1)2 + (SEM2)2]
Confidence intervals for the difference between two population means
Confidence intervals for the difference between two population proportions
Interpretation of a confidence interval
