For Exercises 13–20, do the following for the indicated data set:

  1. Construct a scatterplot of the relationship between and .
  2. Interpret the scatterplot.
  3. Calculate the correlation coefficient .
  4. Interpret the value of the correlation coefficient .

Question 4.13

13. The values of and are as follows:

10 2
20 2
30 3
40 4
50 4

4.1.13

(a)

image

(b) The variables and have a positive linear relationship. (c) (d) This value of is very close to the maximum value . We would therefore say that and are positively correlated. As increases, also tends to increase.