Finding the Fourth Proportional to 8,311.45, 12,478.71 and 5,203.69

Step by Step Solution

1. Step 1: Write the proportion equation
   8,311.45 : 12,478.71 = 5,203.69 : x
2. Step 2: Convert to fraction form
   8,311.45/12,478.71 = 5,203.69/x
3. Step 3: Cross multiply
   8,311.45x = 12,478.71 × 5,203.69
4. Step 4: Simplify right side
   8,311.45x = 64,935,400.61
5. Step 5: Solve for x
   x = 64,935,400.61/8,311.45
6. Step 6: Final answer
   x = 7,812.76