Finding the Fourth Proportional to 10,200.78, 15,286.79 and 8,111.52

Step by Step Solution

1. Step 1: Write the proportion equation
   10,200.78 : 15,286.79 = 8,111.52 : x
2. Step 2: Convert to fraction form
   10,200.78/15,286.79 = 8,111.52/x
3. Step 3: Cross multiply
   10,200.78x = 15,286.79 × 8,111.52
4. Step 4: Simplify right side
   10,200.78x = 123,999,123.10
5. Step 5: Solve for x
   x = 123,999,123.10/10,200.78
6. Step 6: Final answer
   x = 12,155.85