Finding the Fourth Proportional to 12,456.45, 17,138.40 and 9,454.80

Step by Step Solution

1. Step 1: Write the proportion equation
   12,456.45 : 17,138.40 = 9,454.80 : x
2. Step 2: Convert to fraction form
   12,456.45/17,138.40 = 9,454.80/x
3. Step 3: Cross multiply
   12,456.45x = 17,138.40 × 9,454.80
4. Step 4: Simplify right side
   12,456.45x = 162,040,144.32
5. Step 5: Solve for x
   x = 162,040,144.32/12,456.45
6. Step 6: Final answer
   x = 13,008.53