Question

For continuous and categorical data, which graphs are most appropriate to use for each. Why?

Answer 1

a)

Like bar graphs, pie charts are best used with categorical data to help us see what percentage of the whole each category constitutes. Pie charts require all categories to be included in a graph

b)

Two categorical variables

• Use frequency table
  • One categorical variable and other continuous variable
• Box plots of continuous variable values for each category of categorical variable
• Side-by-side dot plots (means + measure of uncertainty, SE or confidence interval)
  • Do not link means across categories!

Two continuous variables

• Scatter plot of raw data if sample size is not too large
• Prediction with confidence bands

1. In the table below, match the following types of graphs with the types of variables used to create the graphs.

Type of Graph	Type of Variable
a. Histogram	_____ discrete
b. Stem-and-leaf plot	_____ discrete
c. Broken-line graph	_____ discrete
d. Bar graph	_____ continuous
e. Pie chart	_____ continuous

1. In the table below, match the following types of graphs with the types of variables used to create the graphs.

Type of Graph	Type of Variable
a. Broken-line graph	_____ qualitative
b. Bar graph	_____ numerical
c. Pie chart	_____ categorical
d. Stem-and-leaf plot	_____ quantitative
e. Histogram	_____ numerical