Finding the Fourth Proportional to 13,099.50, 18,077.28 and 7,131.21

Step by Step Solution

1. Step 1: Write the proportion equation
   13,099.50 : 18,077.28 = 7,131.21 : x
2. Step 2: Convert to fraction form
   13,099.50/18,077.28 = 7,131.21/x
3. Step 3: Cross multiply
   13,099.50x = 18,077.28 × 7,131.21
4. Step 4: Simplify right side
   13,099.50x = 128,912,879.91
5. Step 5: Solve for x
   x = 128,912,879.91/13,099.50
6. Step 6: Final answer
   x = 9,841.05