Finding the Fourth Proportional to 2,639.06, 3,957.78 and 1,251.98

Step by Step Solution

1. Step 1: Write the proportion equation
   2,639.06 : 3,957.78 = 1,251.98 : x
2. Step 2: Convert to fraction form
   2,639.06/3,957.78 = 1,251.98/x
3. Step 3: Cross multiply
   2,639.06x = 3,957.78 × 1,251.98
4. Step 4: Simplify right side
   2,639.06x = 4,955,061.40
5. Step 5: Solve for x
   x = 4,955,061.40/2,639.06
6. Step 6: Final answer
   x = 1,877.59