2.46 Strong association but no correlation. Here is a data set that illustrates an important point about correlation:

X 25 35 45 55 65
Y 10 30 50 30 10

  1. (a) Make a scatterplot of Y versus X.

  2. (b) Describe the relationship between Y and X. Is it weak or strong? Is it linear?

  3. (c) Find the correlation between Y and X.

  4. (d) What important point about correlation does this exercise illustrate?