Finding the Fourth Proportional to 12,818.28, 17,688.42 and 7,153.86

Step by Step Solution

1. Step 1: Write the proportion equation
   12,818.28 : 17,688.42 = 7,153.86 : x
2. Step 2: Convert to fraction form
   12,818.28/17,688.42 = 7,153.86/x
3. Step 3: Cross multiply
   12,818.28x = 17,688.42 × 7,153.86
4. Step 4: Simplify right side
   12,818.28x = 126,540,480.30
5. Step 5: Solve for x
   x = 126,540,480.30/12,818.28
6. Step 6: Final answer
   x = 9,871.88