Finding the Fourth Proportional to 8,139.42, 12,208.59 and 4,872.78

Step by Step Solution

1. Step 1: Write the proportion equation
   8,139.42 : 12,208.59 = 4,872.78 : x
2. Step 2: Convert to fraction form
   8,139.42/12,208.59 = 4,872.78/x
3. Step 3: Cross multiply
   8,139.42x = 12,208.59 × 4,872.78
4. Step 4: Simplify right side
   8,139.42x = 59,489,773.18
5. Step 5: Solve for x
   x = 59,489,773.18/8,139.42
6. Step 6: Final answer
   x = 7,308.85