Finding the Fourth Proportional to 2,682.72, 3,990.06 and 2,648.70

Step by Step Solution

1. Step 1: Write the proportion equation
   2,682.72 : 3,990.06 = 2,648.70 : x
2. Step 2: Convert to fraction form
   2,682.72/3,990.06 = 2,648.70/x
3. Step 3: Cross multiply
   2,682.72x = 3,990.06 × 2,648.70
4. Step 4: Simplify right side
   2,682.72x = 10,568,471.92
5. Step 5: Solve for x
   x = 10,568,471.92/2,682.72
6. Step 6: Final answer
   x = 3,939.46