Finding the Fourth Proportional to 2,874.71, 4,308.89 and 1,639.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,874.71 : 4,308.89 = 1,639.40 : x
2. Step 2: Convert to fraction form
   2,874.71/4,308.89 = 1,639.40/x
3. Step 3: Cross multiply
   2,874.71x = 4,308.89 × 1,639.40
4. Step 4: Simplify right side
   2,874.71x = 7,063,964.52
5. Step 5: Solve for x
   x = 7,063,964.52/2,874.71
6. Step 6: Final answer
   x = 2,457.28