Suppose that for a company manufacturing calculators, the cost, revenue, and profit equations are given by Start 1 By 3 Matrix 1st Row 1st Column Upper C equals 90 comma 000 plus 20 x comma Superscript 2nd Column Upper R equals 300 x minus StartFraction x squared Over 20 EndFraction comma 3rd Column Upper P equals Upper R minus Upper C Superscript EndMatrix where the production output in 1 week is x calculators. If production is increasing at a rate of 500 calculators per week when production output is 4 comma 000 calculators. Find the rate of increase (decrease) in cost, revenue, and profit.