Finding the Fourth Proportional to 42,439.62, 63,644.37 and 12,445.50

Step by Step Solution

1. Step 1: Write the proportion equation
   42,439.62 : 63,644.37 = 12,445.50 : x
2. Step 2: Convert to fraction form
   42,439.62/63,644.37 = 12,445.50/x
3. Step 3: Cross multiply
   42,439.62x = 63,644.37 × 12,445.50
4. Step 4: Simplify right side
   42,439.62x = 792,086,006.84
5. Step 5: Solve for x
   x = 792,086,006.84/42,439.62
6. Step 6: Final answer
   x = 18,663.83