Finding the Fourth Proportional to 13,139.61, 18,132.52 and 7,171.23

Step by Step Solution

1. Step 1: Write the proportion equation
   13,139.61 : 18,132.52 = 7,171.23 : x
2. Step 2: Convert to fraction form
   13,139.61/18,132.52 = 7,171.23/x
3. Step 3: Cross multiply
   13,139.61x = 18,132.52 × 7,171.23
4. Step 4: Simplify right side
   13,139.61x = 130,032,471.40
5. Step 5: Solve for x
   x = 130,032,471.40/13,139.61
6. Step 6: Final answer
   x = 9,896.22