Finding the Fourth Proportional to 12,838.78, 17,708.03 and 8,118.50

Step by Step Solution

1. Step 1: Write the proportion equation
   12,838.78 : 17,708.03 = 8,118.50 : x
2. Step 2: Convert to fraction form
   12,838.78/17,708.03 = 8,118.50/x
3. Step 3: Cross multiply
   12,838.78x = 17,708.03 × 8,118.50
4. Step 4: Simplify right side
   12,838.78x = 143,762,641.56
5. Step 5: Solve for x
   x = 143,762,641.56/12,838.78
6. Step 6: Final answer
   x = 11,197.54