John works in an appliance store. His sales commission depends on the number of units sold per period and the overall average price of all units sold. The following is a report of his sales effort in a given month. The report shows the price and the percent of total units sold at that price.
Percent of total units Item Price
10% $1,250
20% $1,020
25% $680
25% $350
10% $200
The overall mean price of all items sold is $646.