Finding the Fourth Proportional to 8,607.40, 12,910.02 and 5,478.10

Step by Step Solution

1. Step 1: Write the proportion equation
   8,607.40 : 12,910.02 = 5,478.10 : x
2. Step 2: Convert to fraction form
   8,607.40/12,910.02 = 5,478.10/x
3. Step 3: Cross multiply
   8,607.40x = 12,910.02 × 5,478.10
4. Step 4: Simplify right side
   8,607.40x = 70,722,380.56
5. Step 5: Solve for x
   x = 70,722,380.56/8,607.40
6. Step 6: Final answer
   x = 8,216.46