Finding the Fourth Proportional to 13,131.80, 18,121.83 and 7,163.42

Step by Step Solution

1. Step 1: Write the proportion equation
   13,131.80 : 18,121.83 = 7,163.42 : x
2. Step 2: Convert to fraction form
   13,131.80/18,121.83 = 7,163.42/x
3. Step 3: Cross multiply
   13,131.80x = 18,121.83 × 7,163.42
4. Step 4: Simplify right side
   13,131.80x = 129,814,263.92
5. Step 5: Solve for x
   x = 129,814,263.92/13,131.80
6. Step 6: Final answer
   x = 9,885.49