Finding the Fourth Proportional to 12,312.07, 18,464.22 and 3,990.15

Step by Step Solution

1. Step 1: Write the proportion equation
   12,312.07 : 18,464.22 = 3,990.15 : x
2. Step 2: Convert to fraction form
   12,312.07/18,464.22 = 3,990.15/x
3. Step 3: Cross multiply
   12,312.07x = 18,464.22 × 3,990.15
4. Step 4: Simplify right side
   12,312.07x = 73,675,007.43
5. Step 5: Solve for x
   x = 73,675,007.43/12,312.07
6. Step 6: Final answer
   x = 5,983.97