Finding the Fourth Proportional to 12,128.78, 18,158.34 and 10,862.48

Step by Step Solution

1. Step 1: Write the proportion equation
   12,128.78 : 18,158.34 = 10,862.48 : x
2. Step 2: Convert to fraction form
   12,128.78/18,158.34 = 10,862.48/x
3. Step 3: Cross multiply
   12,128.78x = 18,158.34 × 10,862.48
4. Step 4: Simplify right side
   12,128.78x = 197,244,605.08
5. Step 5: Solve for x
   x = 197,244,605.08/12,128.78
6. Step 6: Final answer
   x = 16,262.53