Finding the Fourth Proportional to 42,371.70, 63,557.94 and 12,789.78

Step by Step Solution

1. Step 1: Write the proportion equation
   42,371.70 : 63,557.94 = 12,789.78 : x
2. Step 2: Convert to fraction form
   42,371.70/63,557.94 = 12,789.78/x
3. Step 3: Cross multiply
   42,371.70x = 63,557.94 × 12,789.78
4. Step 4: Simplify right side
   42,371.70x = 812,892,069.85
5. Step 5: Solve for x
   x = 812,892,069.85/42,371.70
6. Step 6: Final answer
   x = 19,184.79