Finding the Fourth Proportional to 12,686.96, 17,502.15 and 8,212.15

Step by Step Solution

1. Step 1: Write the proportion equation
   12,686.96 : 17,502.15 = 8,212.15 : x
2. Step 2: Convert to fraction form
   12,686.96/17,502.15 = 8,212.15/x
3. Step 3: Cross multiply
   12,686.96x = 17,502.15 × 8,212.15
4. Step 4: Simplify right side
   12,686.96x = 143,730,333.80
5. Step 5: Solve for x
   x = 143,730,333.80/12,686.96
6. Step 6: Final answer
   x = 11,328.98