Download MA155 Statistical Reasoning Study Guide for test over Chapter 3

MA155 Statistical Reasoning
Study Guide for test over Chapter 3, 4.1 to 4.3, Chapter 5
You should be able to:
3.1 Frequency Tables
 Construct a frequency table using bins.
 Use a frequency table to find the relative frequency of each category.
 Use a frequency table to find the cumulative frequency of each category.
3.2 Picturing Distributions of Data
 Construct the following graphs: bar graph, dot plot, pareto chart, pie chart, histogram, stemplot, and line chart.
Be sure to use the appropriate labels (see green box on page 100).
 Understand the situations in which you would use the graphs listed above and be able to read and interpret the
information given in the graph.
 Understand when a graph is also a time-series diagram.
3.3 Graphics in the Media
 Read and interpret multiple bar graphs, multiple line charts, stack plots, graphs with geographical data 3-D
graphics and the combination of the above.
3.4 A Few Cautions About Graphics
 Identify problems with graphs such as perceptual distortions, misleading scales and pictographs.
Good problems to practice: page 134 Chapter Review #1-6, page 135 Chapter Quiz #1-10
4.1 What is Average?
 Find and interpret the following measures of center or “averages”—mean, median, and mode.
Understand which “average” is the appropriate one to use in a given situation. For example: median is
appropriate to use when discussing family income, since a few high incomes (outliers) would raise the
mean. Median would be a better representation of what the “average” family earns.
 Understand the relationship between mean, median and mode (see blue box on page 149).
 Understand the “Rounding Rule for Statistical Calculations” (see green box on page 147).
 Understand what is meant by an outlier.
 Be able to calculate a weighted mean.
 Be able to calculate the mean and median from binned data.
4.2 Shapes of Distributions
 Be able to classify a distribution by:
1. The number of modes
A. Uniform distribution—no mode
B. Single peaked or unimodal
C. Bimodal
2. Symmetry or skewness
A. Symmetry—uniform, bell shaped (normal), maybe multiple modes
B. Skewness—left-skewed or right-skewed
3. Variation
 Understand the relationship between mean, median, and mode on symmetric and skewed
distributions (see graphs at bottom of page 159).
4.3 Measures of Variation
 Be able to find and interpret the following measures of variation:
1. Range
2. Interquartile Range (IQR)
3. Standard deviation—you will be given the formula
and asked to find the standard
deviation from a small (5 values or less) set of data.
 Find and interpret the five-number summary (see green box on page 167).
 Use the five-number summary to draw a boxplot. Understand what a boxplot tells you about the
shape of a distribution.
 Use IQR and 5-number summary to determine outliers. See notes, but remember outliers are values
less than
or values greater than
 Understand what is meant by a percentile.
 Use the range rule of thumb to approximate the standard deviation.
Good problems to practice: page 186 Chapter Test #1-3, Chapter Test #1-10