Finding the Fourth Proportional to 42,470.86, 63,709.29 and 12,891.10

Step by Step Solution

1. Step 1: Write the proportion equation
   42,470.86 : 63,709.29 = 12,891.10 : x
2. Step 2: Convert to fraction form
   42,470.86/63,709.29 = 12,891.10/x
3. Step 3: Cross multiply
   42,470.86x = 63,709.29 × 12,891.10
4. Step 4: Simplify right side
   42,470.86x = 821,282,828.32
5. Step 5: Solve for x
   x = 821,282,828.32/42,470.86
6. Step 6: Final answer
   x = 19,337.56