4 A foundry receives an order for three custom-designed castings. The customer will pay $30,000 for each of four good castings. The customer will accept neither fewer nor more than three castings. It will cost $10,000 to produce each casting. Each casting is produced independently; the probability of a casting being good is estimated to be 0.90. write the cost Revenue and profit equations. How ?many castings should be produced (O ) () ) (5 )