Finding the Fourth Proportional to 12,209.80, 16,850.82 and 9,380.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,209.80 : 16,850.82 = 9,380.20 : x
2. Step 2: Convert to fraction form
   12,209.80/16,850.82 = 9,380.20/x
3. Step 3: Cross multiply
   12,209.80x = 16,850.82 × 9,380.20
4. Step 4: Simplify right side
   12,209.80x = 158,064,061.76
5. Step 5: Solve for x
   x = 158,064,061.76/12,209.80
6. Step 6: Final answer
   x = 12,945.67