Finding the Fourth Proportional to 8,311.68, 12,470.51 and 5,145.43

Step by Step Solution

1. Step 1: Write the proportion equation
   8,311.68 : 12,470.51 = 5,145.43 : x
2. Step 2: Convert to fraction form
   8,311.68/12,470.51 = 5,145.43/x
3. Step 3: Cross multiply
   8,311.68x = 12,470.51 × 5,145.43
4. Step 4: Simplify right side
   8,311.68x = 64,166,153.73
5. Step 5: Solve for x
   x = 64,166,153.73/8,311.68
6. Step 6: Final answer
   x = 7,720.00