need help with the following

An auto supplies company has retail stores located in eight cities in California. The price they charge for a particular product in each city varies because of differing competitive conditions. For instance, the price they charge for a case of a popular brand of motor oil in each city follows. Also shown are the number of cases that the company sold last quarter in each city. City Price ($) Sales (cases) Bakersfield 34.99 451 Los Angeles 38.99 1,425 Modesto 36.00 204 Oakland 33.59 872 Sacramento 40.99 635 San Diego 38.59 1,168 San Francisco 39.59 1,644 San Jose 37.99 799 Compute the average sales price per case for this product during the last quarter. (Round your answer to two decimal places.) $