Finding the Fourth Proportional to 8,623.87, 12,860.34 and 8,545.05

Step by Step Solution

1. Step 1: Write the proportion equation
   8,623.87 : 12,860.34 = 8,545.05 : x
2. Step 2: Convert to fraction form
   8,623.87/12,860.34 = 8,545.05/x
3. Step 3: Cross multiply
   8,623.87x = 12,860.34 × 8,545.05
4. Step 4: Simplify right side
   8,623.87x = 109,892,248.32
5. Step 5: Solve for x
   x = 109,892,248.32/8,623.87
6. Step 6: Final answer
   x = 12,742.80