Finding the Fourth Proportional to 8,641.50, 12,890.42 and 8,498.81

Step by Step Solution

1. Step 1: Write the proportion equation
   8,641.50 : 12,890.42 = 8,498.81 : x
2. Step 2: Convert to fraction form
   8,641.50/12,890.42 = 8,498.81/x
3. Step 3: Cross multiply
   8,641.50x = 12,890.42 × 8,498.81
4. Step 4: Simplify right side
   8,641.50x = 109,553,123.45
5. Step 5: Solve for x
   x = 109,553,123.45/8,641.50
6. Step 6: Final answer
   x = 12,677.56