Finding the Fourth Proportional to 10,611.30, 15,978.61 and 7,857.48

Step by Step Solution

1. Step 1: Write the proportion equation
   10,611.30 : 15,978.61 = 7,857.48 : x
2. Step 2: Convert to fraction form
   10,611.30/15,978.61 = 7,857.48/x
3. Step 3: Cross multiply
   10,611.30x = 15,978.61 × 7,857.48
4. Step 4: Simplify right side
   10,611.30x = 125,551,588.86
5. Step 5: Solve for x
   x = 125,551,588.86/10,611.30
6. Step 6: Final answer
   x = 11,831.88