4. Hanse, Inc., has the following two mutually exclusive projects available. Year ONMtu 1 2 3 4 5 Project R -$ 82,000 28,800 27,800 25,800 19,800 10,600 Project S -$101,600 25,400 25,400 40,400 35,400 14,400 a) What is the crossover rate for these projects? b) What is the NPV of each project at the crossover rate