3. (10 points) John Sobieski, third of his name, is the King of Poland. Under the threat of a great war with the neighboring Ottoman Empire, he borrows X from a local noble to modernize his cavalry regiments. He is to repay the principal by making 20 level annual payments at the end of each year into a sinking fund which earns an annual effective rate of 10%. The interest earned in the sinking fund during the 4th year is 86.06. Calculate X