Finding the Fourth Proportional to 12,456.40, 17,186.35 and 7,149.28

Step by Step Solution

1. Step 1: Write the proportion equation
   12,456.40 : 17,186.35 = 7,149.28 : x
2. Step 2: Convert to fraction form
   12,456.40/17,186.35 = 7,149.28/x
3. Step 3: Cross multiply
   12,456.40x = 17,186.35 × 7,149.28
4. Step 4: Simplify right side
   12,456.40x = 122,870,028.33
5. Step 5: Solve for x
   x = 122,870,028.33/12,456.40
6. Step 6: Final answer
   x = 9,864.01