Finding the Fourth Proportional to 20,889.69, 31,345.31 and 13,874.55

Step by Step Solution

1. Step 1: Write the proportion equation
   20,889.69 : 31,345.31 = 13,874.55 : x
2. Step 2: Convert to fraction form
   20,889.69/31,345.31 = 13,874.55/x
3. Step 3: Cross multiply
   20,889.69x = 31,345.31 × 13,874.55
4. Step 4: Simplify right side
   20,889.69x = 434,901,844.76
5. Step 5: Solve for x
   x = 434,901,844.76/20,889.69
6. Step 6: Final answer
   x = 20,818.98