A Hong Kong snack-food vendor offers 3 types of boxed ”lunches to go,” priced at $3, $5, and $10, respectively. The vendor would like to establish whether there is a relationship between the price of...

A Hong Kong snack-food vendor offers 3 types of boxed ”lunches to go,” priced at $3, $5, and $10, respectively. The vendor would like to establish whether there is a relationship between the price of the boxed lunch and the number of sales achieved per hour. Consequently, over a 15-day period the vendor records the number of sales made for each of the 3 types of boxed lunches. The following data show the boxed-lunch price (x) and the number sold (y) during each of the 15 lunch hours.