Finding the Fourth Proportional to 2,720.88, 4,078.46 and 1,261

Step by Step Solution

1. Step 1: Write the proportion equation
   2,720.88 : 4,078.46 = 1,261 : x
2. Step 2: Convert to fraction form
   2,720.88/4,078.46 = 1,261/x
3. Step 3: Cross multiply
   2,720.88x = 4,078.46 × 1,261
4. Step 4: Simplify right side
   2,720.88x = 5,142,938.06
5. Step 5: Solve for x
   x = 5,142,938.06/2,720.88
6. Step 6: Final answer
   x = 1,890.17