Chapter 4.2, Problem 4.49E

To determine

To construct the scatterplot of the weight of the bar of soap against day and tell that the overall pattern roughly a straight line or not and also is the correlation between day and weight close to $1$ , positive but not close to $1$ , close to zero, negative but not close to $-1$ , or close to $-1$ .

Answer to Problem 4.49E

Yes, close to $-1$ .

Explanation of Solution

The scatterplot of the weight of the bar of soap against day is as follows:

  

And yes the overall pattern of the scatterplot is roughly a straight line.

Since the points follow roughly a line, $\left|r\right|$ is very close to $1$ . Since the scatterplot slopes downwards, the linear correlation coefficient also has to be negative. Thus $r$ is close to $-1$ .