STAT 100, Section 4: Statistical Concepts and Reasoning
Fall 2008
Exam 1: Wednesday, Sept. 24
This exam will be worth
100 points (out of 500 for the whole course).
Students are responsible for all material covered in lectures
and all material in Chapters 1, 3, 4, 5, 7, and 8 of the textbook.
There
are some sample exam 1 questions
available, along with answers
to most of the questions.
Update
Now that the exam has occurred, you may stop by to pick up your exams if you wish. Here are
the answers to all ten exam versions:
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 1
Definition of the term "statistics"
Definitions: population, sample
Observational study vs. randomized experiment
Randomized experiments allow the inference of causation
Dangers of attempting to infer causation from observational studies
Chapter 7
Graphical and numerical summaries
Types of graphs for measurement data; their
advantages and disadvantages
Stemplot (order the data, etc.)
Histograms (evaluating the shape of the data)
Boxplots (detecting outliers, comparing two or more samples by
examining medians, IQRs, outliers)
Possible shapes of histograms
Numerical measures of center (mean, median, mode)
Numerical measures of spread (standard deviation, IQR)
Five-number summary
Calculating the IQR when given appropriate quartiles
Interpretation of the IQR
Determine shape of data: by comparing mean to median
Comparing two samples using boxplots
Chapter 8
Standard normal distribution
Basic components of the Empirical Rule (or the 68-95-99.7 Rule)
Calculation and interpretation of standardized scores (z-scores)
Solving for a percentile from observed value
Solving for an observed score when given a percentile
Normal table on page 157 of the textbook
will be provided; know how to use it.
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 4
Difference between population and sample
Sample surveys
Understand definitions of terms on page 61 of the textbook
Calculation and interpretation of a margin of error (including
knowing the formula)
Sampling methods discussed in class
"Difficulties and Disasters" in sampling
Principles applied in the Gallup Poll (talked about in class)
Chapter 5
Definitions of: Explanatory variable, response
variable, treatment
Randomized experiment vs. observational study
Block designs (Blocking) and Matched Pairs - when is it used - what does it accomplish
Placebos, placebo effect
Single-blinded and double-blinded experiments
Confounding variables
Hawthorne effect
Retrospective study vs. prospective study
Case-control study (Identify and recognize advantages as a type of an observational study)
Interacting variables
Ecological validity
Random sample vs. random assignment
