Graphing

Read these sections and complete the questions at the end of each section. First, we'll look at the available methods to portray distributions of quantitative variables. Then, we'll introduce the stem and leaf plot and how to capture the frequency of your data. We'll also discuss box plots for the purpose of identifying outliers and for comparing distributions and bar charts for quantitative variables. Finally, we'll talk about line graphs, which are based on bar graphs.

Histograms

Questions

Question 1 out of 2.

When discussing a histogram, what does "bin width" mean?

• The result of subtracting the smallest observation from the largest.
• The average number of scores falling into each interval.
• The amount of "skew" shown by the distribution.
• The result of dividing the range of scores by the number of classes.

Question 2 out of 2.

If you apply Sturges' rule to a data set including 4000 observations, how many intervals should your histogram have?

• The top of the box.
• The base 2 logarithm of 4096 (which is close to 4000) is 13, so Sturges' rule recommends 13 + 1 or 14 intervals.
• We should have 11 intervals because this is 1 less than the base 2 logarithm of 4000.
• According to Sturges' rule, there should be 13 intervals because the base 2 logarithm of 4096 (which is close to 4000) is 12.