Finding the Fourth Proportional to 8,621.72, 12,934.61 and 2,778.11

Step by Step Solution

1. Step 1: Write the proportion equation
   8,621.72 : 12,934.61 = 2,778.11 : x
2. Step 2: Convert to fraction form
   8,621.72/12,934.61 = 2,778.11/x
3. Step 3: Cross multiply
   8,621.72x = 12,934.61 × 2,778.11
4. Step 4: Simplify right side
   8,621.72x = 35,933,690.82
5. Step 5: Solve for x
   x = 35,933,690.82/8,621.72
6. Step 6: Final answer
   x = 4,167.81