Finding the Fourth Proportional to 2,647.92, 3,971.92 and 1,261.40

Step by Step Solution

1. Step 1: Write the proportion equation
   2,647.92 : 3,971.92 = 1,261.40 : x
2. Step 2: Convert to fraction form
   2,647.92/3,971.92 = 1,261.40/x
3. Step 3: Cross multiply
   2,647.92x = 3,971.92 × 1,261.40
4. Step 4: Simplify right side
   2,647.92x = 5,010,179.89
5. Step 5: Solve for x
   x = 5,010,179.89/2,647.92
6. Step 6: Final answer
   x = 1,892.12