Finding the Fourth Proportional to 3,105.72, 4,659.12 and 2,782.80

Step by Step Solution

1. Step 1: Write the proportion equation
   3,105.72 : 4,659.12 = 2,782.80 : x
2. Step 2: Convert to fraction form
   3,105.72/4,659.12 = 2,782.80/x
3. Step 3: Cross multiply
   3,105.72x = 4,659.12 × 2,782.80
4. Step 4: Simplify right side
   3,105.72x = 12,965,399.14
5. Step 5: Solve for x
   x = 12,965,399.14/3,105.72
6. Step 6: Final answer
   x = 4,174.68