Finding the Fourth Proportional to 2,683.91, 4,003.57 and 2,639.36

Step by Step Solution

1. Step 1: Write the proportion equation
   2,683.91 : 4,003.57 = 2,639.36 : x
2. Step 2: Convert to fraction form
   2,683.91/4,003.57 = 2,639.36/x
3. Step 3: Cross multiply
   2,683.91x = 4,003.57 × 2,639.36
4. Step 4: Simplify right side
   2,683.91x = 10,566,862.52
5. Step 5: Solve for x
   x = 10,566,862.52/2,683.91
6. Step 6: Final answer
   x = 3,937.12