Two annuity immediates in perpetuity have a present value of $5,000 and a common effective annual interest rate. The first annuity makes payments of X at the end of every 4 years while the second...

Two annuity immediates in perpetuity have a present value of $5,000 and a common effective annual interest rate. The first annuity makes payments of X at the end of every 4 years while the second makes payment of $50 at the end of every two months. Find X.