Exam 1 Study Guide
STAT 200
For each of the topics below, look over the relevant problems in your lecture notes and
homework. Exams will be done entirely with “pen and paper,” and the use of a calculator is
allowed and encouraged.
Chapter 1 – Data
• Types of variables: numeric (discrete, continuous); categorical (ordinal, unordered); logical
• Missing values
• R things to know:
R as a calculator, sqrt(), sin(), cos(), exp(), log()
=, <-, ->
c(), seq(), :, rep(), rev()
length(),sum(), min(), max(), range(), sort()
help(), ?, help.search()
() versus []
==, >=, <=, >, <, !=
&, |, !, %in%
which(), with()
Using logical operators and which() inside of []
NA, is.na()
library(), attach(), detach(), dim(), names(), $
read.table(), read.csv()
Chapter 2 – Univariate Data
• Using a table to display frequency and/or proportion of a categorical variable.
• Be able to creating and read a barplot (bar graph)
• Be able to creating and read a stem-and-leaf plot.
• Measures of center: mean, trimmed mean, median, mode
- Be able to calculate
- How do mean, trimmed mean, median behave with presence of extreme values
• Measures of variation: variance, standard deviation, range, IQR
- Be able to calculate
- Which variation measure goes with which center measure
• Explain how the mean and SD change when various changes are made to a distribution:
o A constant is added/subtracted to every number in the list
o All numbers are multiplied/divided by the same value
• Quantiles/Percentiles – the pth quantile is the theoretical value with proportion p of the data
less than it
- Be able to calculate
- Five number summary
• Boxplots (box-and-whisker plots)
- Be able to read and interpret
- Be able to draw
• Histograms
- Be able to read and interpret
