Finding the Fourth Proportional to 2,688.15, 4,003.86 and 2,568.21

Step by Step Solution

1. Step 1: Write the proportion equation
   2,688.15 : 4,003.86 = 2,568.21 : x
2. Step 2: Convert to fraction form
   2,688.15/4,003.86 = 2,568.21/x
3. Step 3: Cross multiply
   2,688.15x = 4,003.86 × 2,568.21
4. Step 4: Simplify right side
   2,688.15x = 10,282,753.29
5. Step 5: Solve for x
   x = 10,282,753.29/2,688.15
6. Step 6: Final answer
   x = 3,825.22