Finding the Fourth Proportional to 31,415.50, 47,144.85 and 12,947.50

Step by Step Solution

1. Step 1: Write the proportion equation
   31,415.50 : 47,144.85 = 12,947.50 : x
2. Step 2: Convert to fraction form
   31,415.50/47,144.85 = 12,947.50/x
3. Step 3: Cross multiply
   31,415.50x = 47,144.85 × 12,947.50
4. Step 4: Simplify right side
   31,415.50x = 610,407,945.38
5. Step 5: Solve for x
   x = 610,407,945.38/31,415.50
6. Step 6: Final answer
   x = 19,430.15