Finding the Fourth Proportional to 13,144.23, 18,139.02 and 8,428.50

Step by Step Solution

1. Step 1: Write the proportion equation
   13,144.23 : 18,139.02 = 8,428.50 : x
2. Step 2: Convert to fraction form
   13,144.23/18,139.02 = 8,428.50/x
3. Step 3: Cross multiply
   13,144.23x = 18,139.02 × 8,428.50
4. Step 4: Simplify right side
   13,144.23x = 152,884,730.07
5. Step 5: Solve for x
   x = 152,884,730.07/13,144.23
6. Step 6: Final answer
   x = 11,631.32