Finding the Fourth Proportional to 12,685.25, 17,499.78 and 8,210.45

Step by Step Solution

1. Step 1: Write the proportion equation
   12,685.25 : 17,499.78 = 8,210.45 : x
2. Step 2: Convert to fraction form
   12,685.25/17,499.78 = 8,210.45/x
3. Step 3: Cross multiply
   12,685.25x = 17,499.78 × 8,210.45
4. Step 4: Simplify right side
   12,685.25x = 143,680,981.20
5. Step 5: Solve for x
   x = 143,680,981.20/12,685.25
6. Step 6: Final answer
   x = 11,326.62