The following summary is adapted from by Peck, Olsen, & Devore Introduction to Statistics & Data Analysis and from by Yates, Moore, & McCabe. You may find that you need to add more The Practice of Statistics clarification. When to use: How to make: What to look for: Type of Graph: Categorical Write category names or labels Frequently & Bar graphs data on x-axis at evenly-spaced infrequently intervals occurring Label the y-axis with the categories. frequency or relative frequency Draw bars above each category using the appropriate frequency or relative frequency. (Bars should be equal width.) Categorical Draw a circle Categories that Pie charts data To calculate the number of form large or small degrees for each category, proportions of the (useful for multiply the relative frequencies data set. displaying times parts to Draw in each category’s “slice” whole) and label Numerical Draw a number line and label it Center & spread if Dotplots data appropriately data, type of Place a dot (or X) above the line distribution, & (small sets) for each value in the data set, unusual values stacking the dots vertically Numerical Select one (or more) leading Center & spread if Stem-and Leaf data digits for stem values and list data, type of Plots possible stem values vertically. distribution, & (small to Record the leaf values (trailing unusual values medium sets) digit(s)) beside the corresponding stem value. Indicate the units for stems and leaves somewhere in the plot Discrete Label the x-axis with the Center & spread if Histograms numerical possible data values data, type of data Label the y-axis with the distribution, & frequencies or relative unusual values frequencies Draw a rectangle above each value using the appropriate frequencies or relative frequencies for each value. Be sure to center the rectangle above the value
The following summary is adapted from Introduction to Statistics & Data Analysis by Peck, Olsen, & Devore and from The Practice of Statistics by Yates, Moore, & McCabe. You may find that you need to add more clarification. Type of Graph: When to use: How to make: What to look for: Bar graphs Categorical data Write category names or labels on x-axis at evenly-spaced intervals Label the y-axis with the frequency or relative frequency Draw bars above each category using the appropriate frequency or relative frequency. (Bars should be equal width.) Frequently & infrequently occurring categories. Pie charts Categorical data (useful for displaying parts to whole) Draw a circle To calculate the number of degrees for each category, multiply the relative frequencies times Draw in each category’s “slice” and label Categories that form large or small proportions of the data set. Dotplots Numerical data (small sets) Draw a number line and label it appropriately Place a dot (or X) above the line for each value in the data set, stacking the dots vertically Center & spread if data, type of distribution, & unusual values Stem-and Leaf Plots Numerical data (small to medium sets) Select one (or more) leading digits for stem values and list possible stem values vertically. Record the leaf values (trailing digit(s)) beside the corresponding stem value. Indicate the units for stems and leaves somewhere in the plot Center & spread if data, type of distribution, & unusual values Histograms Discrete numerical data Label the x-axis with the possible data values Label the y-axis with the frequencies or relative frequencies Draw a rectangle above each value using the appropriate frequencies or relative frequencies for each value. Be sure to center the rectangle above the value Center & spread if data, type of distribution, & unusual values