Finding the Fourth Proportional to 81,043.69, 121,565.58 and 21,879.31

Step by Step Solution

1. Step 1: Write the proportion equation
   81,043.69 : 121,565.58 = 21,879.31 : x
2. Step 2: Convert to fraction form
   81,043.69/121,565.58 = 21,879.31/x
3. Step 3: Cross multiply
   81,043.69x = 121,565.58 × 21,879.31
4. Step 4: Simplify right side
   81,043.69x = 2,659,771,010.15
5. Step 5: Solve for x
   x = 2,659,771,010.15/81,043.69
6. Step 6: Final answer
   x = 32,818.98