Aclothing store owner tracks the amount of money the last 10 customers spend in her store. the owner concludes that the typical amount spent by any customer is $28.80. the owner's conclusion a) is valid. the last 10 customers only bought sale items. b) is correct. this is the average amount spent by any customer. c) is invalid. this is not a good representation of all customers. d) is unfair. the last ten people in the store may have been tired.