Finding the Fourth Proportional to 12,390.31, 17,112.82 and 8,160.29

Step by Step Solution

1. Step 1: Write the proportion equation
   12,390.31 : 17,112.82 = 8,160.29 : x
2. Step 2: Convert to fraction form
   12,390.31/17,112.82 = 8,160.29/x
3. Step 3: Cross multiply
   12,390.31x = 17,112.82 × 8,160.29
4. Step 4: Simplify right side
   12,390.31x = 139,645,488.35
5. Step 5: Solve for x
   x = 139,645,488.35/12,390.31
6. Step 6: Final answer
   x = 11,270.54