You get paid on the first day of each month. You cash your check and pay all of your essential expenses. You keep the balance in your “discretionary spending” envelope. A scatter plot shows the number of days that have passed since you were paid and the amount left in your discretionary spending envelope. The explanatory x-variable is the number of days that have passed. The response y-variable is the amount left in your envelope. Is there a positive or negative correlation? Explain.