Finding the Fourth Proportional to 13,139.23, 18,136.16 and 8,105.02

Step by Step Solution

1. Step 1: Write the proportion equation
   13,139.23 : 18,136.16 = 8,105.02 : x
2. Step 2: Convert to fraction form
   13,139.23/18,136.16 = 8,105.02/x
3. Step 3: Cross multiply
   13,139.23x = 18,136.16 × 8,105.02
4. Step 4: Simplify right side
   13,139.23x = 146,993,939.52
5. Step 5: Solve for x
   x = 146,993,939.52/13,139.23
6. Step 6: Final answer
   x = 11,187.41