Finding the Fourth Proportional to 13,139.04, 18,131.72 and 7,170.80

Step by Step Solution

1. Step 1: Write the proportion equation
   13,139.04 : 18,131.72 = 7,170.80 : x
2. Step 2: Convert to fraction form
   13,139.04/18,131.72 = 7,170.80/x
3. Step 3: Cross multiply
   13,139.04x = 18,131.72 × 7,170.80
4. Step 4: Simplify right side
   13,139.04x = 130,018,937.78
5. Step 5: Solve for x
   x = 130,018,937.78/13,139.04
6. Step 6: Final answer
   x = 9,895.62