Question

The owner of a fruit stand gathered data for a week about the number of watermelons, pumpkins, and cantaloupes sold each day. She represented the data in two scatter plots.

Does either scatter plot indicate a positive correlation between the variables?

A.) only plot A
B.) only plot B
C.) both plot A and plot B
D.) neither plot A nor plot B

Answer 1

The answer is A.) only plot A

Answer 2

Answer: A) Only plot A

The reasoning is because all of the points for plot A are fairly close to the same straight line. This straight line has a positive slope. We call this line the regression line.

In contrast, plot B seems to have the points randomly scattered about. We can't draw a good fitting straight line to get near all of the points. So plot B does not show positive linear correlation.

Side note: the correlation coefficient for plot A will have its r value close to 1. The r value for plot B will be close to 0.