What value of x makes the following two cash flow diagrams economically equivalent? Note: interest rate for the first graph is 7% per year, compounded semi-annually. 15% 12 Ex 3x Year 2 5 6 8 $3,000 $1,000 $9,000 $1,000 -7% i-4% 1-4% 0 2 2 3 $2,000