Finding the Fourth Proportional to 10,978.52, 15,140.34 and 9,391.16

Step by Step Solution

1. Step 1: Write the proportion equation
   10,978.52 : 15,140.34 = 9,391.16 : x
2. Step 2: Convert to fraction form
   10,978.52/15,140.34 = 9,391.16/x
3. Step 3: Cross multiply
   10,978.52x = 15,140.34 × 9,391.16
4. Step 4: Simplify right side
   10,978.52x = 142,185,355.39
5. Step 5: Solve for x
   x = 142,185,355.39/10,978.52
6. Step 6: Final answer
   x = 12,951.23