5.6 Consider the investment projects in Table P5.6 all of which have a four-year investment life. TABLE P5.6 Project's Cash Flow (S) 0 $3,800 5,200 $3,800-$2,800 0 $2,200 -$1,600$800 0 $3,800 $6,700 -$,600 0 $4,400 $6,800 $9,400 4 $12,500 $3,600 $6,900 $8,800 (a) What is the payback period of each project? (b) What is the discounted payback period at an interest rate of 15% for each project