Finding the Fourth Proportional to 42,434.78, 63,664.10 and 12,449.73

Step by Step Solution

1. Step 1: Write the proportion equation
   42,434.78 : 63,664.10 = 12,449.73 : x
2. Step 2: Convert to fraction form
   42,434.78/63,664.10 = 12,449.73/x
3. Step 3: Cross multiply
   42,434.78x = 63,664.10 × 12,449.73
4. Step 4: Simplify right side
   42,434.78x = 792,600,793.44
5. Step 5: Solve for x
   x = 792,600,793.44/42,434.78
6. Step 6: Final answer
   x = 18,678.09