Finding the Fourth Proportional to 20,874.31, 31,315.57 and 7,726.80

Step by Step Solution

1. Step 1: Write the proportion equation
   20,874.31 : 31,315.57 = 7,726.80 : x
2. Step 2: Convert to fraction form
   20,874.31/31,315.57 = 7,726.80/x
3. Step 3: Cross multiply
   20,874.31x = 31,315.57 × 7,726.80
4. Step 4: Simplify right side
   20,874.31x = 241,969,146.28
5. Step 5: Solve for x
   x = 241,969,146.28/20,874.31
6. Step 6: Final answer
   x = 11,591.72