I have some data in which some yield percentages are given for different temperatures and stirring rates. I calculate the correlation coefficient (r) in each case. Say $r_1$ is for temperature and yield, $r_2$ is for stirring rate and yield, and $r_3$ is for temperature and stirring rate.
I get $r_1=0.7323$, $r_2=0.7513$, $r_3=0.9064$.
Now, I'm asked if this data provides good evidence that increasing temperature increases yield, and likewise for stirring rate, or is it due to confounding.
I don't understand how to interpret this result. I know that if the correlation coefficient is $1$, then we have a linear correlation. But how to determine whether this correlation is due to confounding or not?