Finding the Fourth Proportional to 2,255.78, 3,113.02 and 1,261.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,255.78 : 3,113.02 = 1,261.12 : x
2. Step 2: Convert to fraction form
   2,255.78/3,113.02 = 1,261.12/x
3. Step 3: Cross multiply
   2,255.78x = 3,113.02 × 1,261.12
4. Step 4: Simplify right side
   2,255.78x = 3,925,887.15
5. Step 5: Solve for x
   x = 3,925,887.15/2,255.78
6. Step 6: Final answer
   x = 1,740.37