Finding the Fourth Proportional to 13,147.23, 18,143.15 and 8,431.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,147.23 : 18,143.15 = 8,431.50 : x
2. Step 2: Convert to fraction form
   13,147.23/18,143.15 = 8,431.50/x
3. Step 3: Cross multiply
   13,147.23x = 18,143.15 × 8,431.50
4. Step 4: Simplify right side
   13,147.23x = 152,973,990.30
5. Step 5: Solve for x
   x = 152,973,990.30/13,147.23
6. Step 6: Final answer
   x = 11,635.45