For Exercises 2.23 and 2.24, see page 75; and for 2.25 and 2.26, see pages 77–78.

Question 2.40

2.40 Stretching a scatterplot

Changing the units of measurement can greatly alter the appearance of a scatterplot. Consider the following data:

stretch

3 4 4
0.5 0.5 0.5
  1. Draw x and y axes each extending from to 6. Plot the data on these axes.
  2. Calculate the values of new variables and , starting from the values of and . Plot against on the same axes using a different plotting symbol. The two plots are very different in appearance.
  3. Find the correlation between and . Then find the correlation between and . How are the two correlations related? Explain why this isn't surprising.