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
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.
