Nike sells a patent golf trainer called the Pitsburg. This device, which sells for $69.95, consists of a metal strip on the floor that is attached to the golfers putter with elastic bands. by taking practice strokes wih the putter attached to the Pitsburg, the golfer learns to feel how the putt should be stroked.

The Pitsburg is sold through a distributor who sells to retail stores ( golf shops and sports outlets ) and to the public through infomercials. The distributor pays nike $30.85 for each Pitsburg. Nike sells them through 30 minutes television informercials and on the Golf channel ( a cable tv channel ) for $69.95 plus $15.95 for shipping and handling. Although each infomercial increases the public awareness of the product, thereby stimulating sales in the retail stores, infomerical sales also preempt retail sales. The distributor sells suficiently large numbers of units that, for every 10 pitsburg sold via the infomerical, two units will not be sold in a retail outlet.

For each unit sold on the infomercial, nike pays $5.80 to the shipping company for mailing and $2 to the phone-answering company for providing the toll - free number and proccesing the order. Nike purchases Pitsburg form the manufacturer, which produces them for $9.55. They are shipped direclty to either the distributor or to the shipping company.

A 30 minute infomercial on the golf channel cost $845,000. Nike has already produced the taped show for the infomercial and is now deciding how many 30 minutes infomercials to purchase over the next three months. THe Golf channel sells that half hour time slots 90 days in advance. From past experience , Nike estimates the first 30 minute informecial will yield 22,000 unit sales. Each subsequent showing of the infomercia will yield only 90% of the units sold follwoing the previous infomercial.

How many 30 minutes infomercials should Nike purchase for the next 90 days?