Essay for a careers in economics

Suppose the number of equipment sales and service contracts that a store sold during the last six (6) months for treadmills and exercise bikes was as follows: treadmill exercise bike total sold 185 123 service contracts 67 55 the store can only sell a service contract on a new piece of equipment. of the 185 treadmills sold, 67 included a service contract and 118 did not.