Finding the Fourth Proportional to 13,100.78, 18,078.65 and 7,132.40

Step by Step Solution

1. Step 1: Write the proportion equation
   13,100.78 : 18,078.65 = 7,132.40 : x
2. Step 2: Convert to fraction form
   13,100.78/18,078.65 = 7,132.40/x
3. Step 3: Cross multiply
   13,100.78x = 18,078.65 × 7,132.40
4. Step 4: Simplify right side
   13,100.78x = 128,944,037.20
5. Step 5: Solve for x
   x = 128,944,037.20/13,100.78
6. Step 6: Final answer
   x = 9,842.47