If an ira is a variable-rate investment for 25 years at rate r percent per year, compounded monthly, then the future value s that accumulates from an initial investment of $1000 is s = 1000 1 + 0.01r 12 300 . what is the rate of change of s with respect to r and what does it tell us if the interest rate is as follows? (round your answers to two decimal places.)

Special order carson manufacturing, inc., sells a single product for $36 per unit. at an operating level of 8,000 units, variable costs are $18 per unit and fixed costs $10 per unit. carson has been offered a price of $20 per unit on a special order of 2,000 units by big mart discount stores, which would use its own brand name on the item. if carson accepts the order, material cost will be $3 less per unit than for regular production. however, special stamping equipment costing $4,000 would be needed to process the order; the equipment would then be discarded. assuming that volume remains within the relevant range, prepare an analysis of differential revenue and costs to determine whether carson should accept the special order. use a negative sign with answer to only indicate an income loss from special order; otherwise do not use negative signs with your answers.