Finding the Fourth Proportional to 9,171.94, 12,657.88 and 5,139.09

Step by Step Solution

1. Step 1: Write the proportion equation
   9,171.94 : 12,657.88 = 5,139.09 : x
2. Step 2: Convert to fraction form
   9,171.94/12,657.88 = 5,139.09/x
3. Step 3: Cross multiply
   9,171.94x = 12,657.88 × 5,139.09
4. Step 4: Simplify right side
   9,171.94x = 65,049,990.95
5. Step 5: Solve for x
   x = 65,049,990.95/9,171.94
6. Step 6: Final answer
   x = 7,092.28