Finding the Fourth Proportional to 10,857.38, 15,086.72 and 10,813.64

Step by Step Solution

1. Step 1: Write the proportion equation
   10,857.38 : 15,086.72 = 10,813.64 : x
2. Step 2: Convert to fraction form
   10,857.38/15,086.72 = 10,813.64/x
3. Step 3: Cross multiply
   10,857.38x = 15,086.72 × 10,813.64
4. Step 4: Simplify right side
   10,857.38x = 163,142,358.86
5. Step 5: Solve for x
   x = 163,142,358.86/10,857.38
6. Step 6: Final answer
   x = 15,025.94