*7. The manufacturing process of a product consists of two successive operations, I and II. The following table provides the pertinent data over the months of June, July, and August:

,,

.,, Finished product demand (units)

Capacity of operation I (hr)

Capacity of operation II (hr)

June 500 800 1000 July 450 700 850 August 600 550 700 Producing a unit of the product takes .6 hour on operation I plus .8 hour on operation II. Overproduction of either the semifinished product (operation I) or the finished product (operation II) in any month is allowed for use in a later month. The corresponding holding costs are $.20 and $.40 per unit per month. The production cost varies by operation and by month. For operation 1, the unit production cost is $10, $12, and

$11 for June, July, and August. For operation 2, the corresponding unit production cost is $15, $18, and $16. Determine the optimal production schedule for the two operations over the 3-month horizon.