Finding the Fourth Proportional to 10,611.55, 15,978.98 and 7,857.73

Step by Step Solution

1. Step 1: Write the proportion equation
   10,611.55 : 15,978.98 = 7,857.73 : x
2. Step 2: Convert to fraction form
   10,611.55/15,978.98 = 7,857.73/x
3. Step 3: Cross multiply
   10,611.55x = 15,978.98 × 7,857.73
4. Step 4: Simplify right side
   10,611.55x = 125,558,510.52
5. Step 5: Solve for x
   x = 125,558,510.52/10,611.55
6. Step 6: Final answer
   x = 11,832.25