An investment club has set a goal of earning 15% on the money it invests in stocks. The members are considering purchasing three possible stocks, with their cost per share (in dollars) and their projected growth per share (in dollars) summarized in the following table. (Let x = computer shares, y = utility shares, and z = retail shares.)

	Stocks
	Computer (x)	Utility (y)	Retail (z)
Cost/share	30	44	26
Growth/share	6.00	6.00	2.40

(a) If they have $392,000 to invest, how many shares of each stock should they buy to meet their goal? (If there are infinitely many solutions, express your answers in terms of z as in Example 3.) (x, y, z) =

(b) If they buy 600 shares of retail stock, how many shares of the other stocks should they buy?

computer	shares
utility	shares

What if they buy 1200 shares of retail stock?

computer	shares
utility	shares

(c) What is the minimum number of shares of computer stock they should buy? shares What is the number of shares of the other stocks in this case?

utility	shares
retail	shares

(d) What is the maximum number of shares of computer stock they should purchase? shares What is the number of shares of the other stocks in this case?

utility	shares
retail	shares