Finding the Fourth Proportional to 13,315,665.68, 18,388,309.60 and 12,590,238.32

Step by Step Solution

1. Step 1: Write the proportion equation
   13,315,665.68 : 18,388,309.60 = 12,590,238.32 : x
2. Step 2: Convert to fraction form
   13,315,665.68/18,388,309.60 = 12,590,238.32/x
3. Step 3: Cross multiply
   13,315,665.68x = 18,388,309.60 × 12,590,238.32
4. Step 4: Simplify right side
   13,315,665.68x = 231,513,200,165,943.91
5. Step 5: Solve for x
   x = 231,513,200,165,943.91/13,315,665.68
6. Step 6: Final answer
   x = 17,386,528.45