Finding the Fourth Proportional to 2,638.88, 3,955.71 and 1,249.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,638.88 : 3,955.71 = 1,249.78 : x
2. Step 2: Convert to fraction form
   2,638.88/3,955.71 = 1,249.78/x
3. Step 3: Cross multiply
   2,638.88x = 3,955.71 × 1,249.78
4. Step 4: Simplify right side
   2,638.88x = 4,943,747.47
5. Step 5: Solve for x
   x = 4,943,747.47/2,638.88
6. Step 6: Final answer
   x = 1,873.43