Researchers found a moderate correlation between the length of a customer's driveway and the size of the tips the customer gave pizza delivery people....

Researchers found a moderate correlation between the length of a customer's driveway and the size of the tips the customer gave pizza delivery people. The longer the driveway, the smaller the tip the delivery person received. The correlation coefficient that most likely represents this relationship would be: -45 I understand that there is a negative correlation but why not -90