Grouper's Lawn Service needs to purchase a new lawnmower costing $8,696 to replace an old lawnmower that cannot be repaired. The new lawnmower is expected to have a useful life of 4 years, with no salvage value at the end of that period. Click here to view the factor table. (a) If Grouper's required rate of return is 12%, what level of annual cash savings must the lawnmower generate to be considered an acceptable investment under the net present value method? (For calculation purposes, use 4 decimal places as displayed in the factor table provided and round final answer to 0 decimal place, e.g. 58,971.) Annual cash savings should be $ (b) If Grouper's required rate of return is 13\%, what level of annual cash savings must the lawnmower generate to be considered an acceptable investment under the net present value method? (For calculation purposes, use 4 decimal places as displayed in the factor table provided and round final answer to 0 decimal place, e.g. 58,971.) Annual cash savings should be $