Using Boston dataset in MASS library, I'm trying to find correlation of all columns against the column medv.
For each column, I'm doing similar to below:
cor(Boston$crim, Boston$medv)
The correlation between crim and medv as calculated above is a negative value. I understand negative values means they are not related closely and therefore the values in crim column is not suitable to use to predict the values in medv column. Which means the Crime Rate (crim) data is not sufficient to predict the Median house pricing (medv).
Did I get that right?
Also, do I have to check each column against medv for correlation? Is there a way to check all columns against medv at once?
Is it ok to say that the highest correlation value would mean that the column is best predictor for medv?