Finding the Fourth Proportional to 2,255.72, 3,113.06 and 1,261.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,255.72 : 3,113.06 = 1,261.20 : x
2. Step 2: Convert to fraction form
   2,255.72/3,113.06 = 1,261.20/x
3. Step 3: Cross multiply
   2,255.72x = 3,113.06 × 1,261.20
4. Step 4: Simplify right side
   2,255.72x = 3,926,191.27
5. Step 5: Solve for x
   x = 3,926,191.27/2,255.72
6. Step 6: Final answer
   x = 1,740.55