Finding the Fourth Proportional to 12,805.38, 17,670.12 and 7,139.59

Step by Step Solution

1. Step 1: Write the proportion equation
   12,805.38 : 17,670.12 = 7,139.59 : x
2. Step 2: Convert to fraction form
   12,805.38/17,670.12 = 7,139.59/x
3. Step 3: Cross multiply
   12,805.38x = 17,670.12 × 7,139.59
4. Step 4: Simplify right side
   12,805.38x = 126,157,323.70
5. Step 5: Solve for x
   x = 126,157,323.70/12,805.38
6. Step 6: Final answer
   x = 9,851.90