00:01
Here we have four scatter plots labeled a, b, c, and d, and we're asked to select all of the correct statements regarding these graphs.
00:10
The first statement says that graph c has a negative correlation.
00:23
So if we look at the graph, we have one variable on the x -axis and one variable on the y -axis.
00:34
And so each dot on the graph shows us the values of each of the two variables for some some single instance.
00:46
And so if we have some correlation line, a regression line, if it has a positive slope, such as the case for a, b, and c, then it has a positive correlation.
00:58
If it has a negative slope, such as the case for d, then it has a negative correlation.
01:04
Now to me c looks like it has very little correlation.
01:08
But since there is a positive sloped line drawn through it, we would say that it's false to say that it has a negative correlation.
01:16
The second statement says that graph b has a higher correlation than graph a.
01:33
So there are two things that matter about a correlation.
01:36
One is the sign of the correlation, positive or negative, that's whether it slopes up or slopes down, and the strength of the correlation, which is how tightly the plotted dots cling to the correlation line or the regression line.
01:53
The closer they lie to the line, the stronger the correlation...