Finding the Fourth Proportional to 31,081.74, 42,899.43 and 20,472.30

Step by Step Solution

1. Step 1: Write the proportion equation
   31,081.74 : 42,899.43 = 20,472.30 : x
2. Step 2: Convert to fraction form
   31,081.74/42,899.43 = 20,472.30/x
3. Step 3: Cross multiply
   31,081.74x = 42,899.43 × 20,472.30
4. Step 4: Simplify right side
   31,081.74x = 878,250,000.79
5. Step 5: Solve for x
   x = 878,250,000.79/31,081.74
6. Step 6: Final answer
   x = 28,256.14