Finding the Fourth Proportional to 12,111.28, 18,132.30 and 8,208.76

Step by Step Solution

1. Step 1: Write the proportion equation
   12,111.28 : 18,132.30 = 8,208.76 : x
2. Step 2: Convert to fraction form
   12,111.28/18,132.30 = 8,208.76/x
3. Step 3: Cross multiply
   12,111.28x = 18,132.30 × 8,208.76
4. Step 4: Simplify right side
   12,111.28x = 148,843,698.95
5. Step 5: Solve for x
   x = 148,843,698.95/12,111.28
6. Step 6: Final answer
   x = 12,289.68