Finding the Fourth Proportional to 8,870.12, 13,308.32 and 3,939.31

Step by Step Solution

1. Step 1: Write the proportion equation
   8,870.12 : 13,308.32 = 3,939.31 : x
2. Step 2: Convert to fraction form
   8,870.12/13,308.32 = 3,939.31/x
3. Step 3: Cross multiply
   8,870.12x = 13,308.32 × 3,939.31
4. Step 4: Simplify right side
   8,870.12x = 52,425,598.06
5. Step 5: Solve for x
   x = 52,425,598.06/8,870.12
6. Step 6: Final answer
   x = 5,910.36