Finding the Fourth Proportional to 20,978.45, 31,467.75 and 8,498.71

Step by Step Solution

1. Step 1: Write the proportion equation
   20,978.45 : 31,467.75 = 8,498.71 : x
2. Step 2: Convert to fraction form
   20,978.45/31,467.75 = 8,498.71/x
3. Step 3: Cross multiply
   20,978.45x = 31,467.75 × 8,498.71
4. Step 4: Simplify right side
   20,978.45x = 267,435,124.26
5. Step 5: Solve for x
   x = 267,435,124.26/20,978.45
6. Step 6: Final answer
   x = 12,748.09