Zippy Cola is studying the effect of its last advertising campaign. People chosen at random were called and asked how many cans of zippy cola they hand bought and advertisements they had either read or seen of zippy cola in the past week Number of ads 3, 7, 4, 2, 0, 4, 1, 2 Cans purchased 11, 18, 9 ,4,7 ,6,3 ,8 what are the independent and dependent variables and also calculate slope and intercept