PRT Electronics manufactures five different models of telecommunications interface cards for personal and laptop computers. As summarized in the following table, each of these devices requires different amounts of printed circuit $($PC$)$ board, resistors, memory chips and assembly.

Per Unit Requirements

HyperLink

FastLink

SpeedLink

MicroLink

EtherLink

PC Board $($square inches$)$

$20$

$15$

$10$

$8$

$5$

Resistors

$28$

$24$

$18$

$12$

$16$

Memory Chips

$8$

$8$

$4$

$4$

$6$

Assembly Labor $($in hours$)$

$0\mathrm{.}75$

$0\mathrm{.}6$

$0\mathrm{.}5$

$0\mathrm{.}65$

$1$

The unit wholesale Price and manufacturing cost for each model are as follows.

Per Unit Revenues and costs

HyperLink

FastLink

SpeedLink

MicroLink

EtherLink

Wholesale Price

$$189$

$$149$

$$129$

$$169$

$$139$

Manufacturing Cost

$$136$

$$101$

$$96$

$$137$

$$101$

In their next production period, PRT has $80,000$ square inches of PC board, $100,000$ resistors, $30,000$ memory chips, and $5,000$ hours of assembly time available. The company wants to sell all the product it can manufacture, but the marketing department wants to be sure that it produces at least $500$ units of each product and at least twice as many FastLink cards as HyperLink cards while maximizing profit.

Formulate an LP model for this problem.

Create a spreadsheet model for this problem and solve it using Solver.

What is the optimal solution?

Could PRT electronics make more money if it schedules its assembly workers to work overtime?

Which of the constraints in the problem are binding?

If the company was going to eliminate one of its products, which should it be$?$

If the company could buy $1,000$ additional memory chips at the usual cost, should they do it$?$ If so$,$ how much would profits increase?

Suppose the manufacturing costs used in this analysis were estimated hastily and are known to be somewhat imprecise. For which products would you want more precise cost estimates before implementing this solution?