Finding the Fourth Proportional to 1,255.28, 1,731.15 and 856.76

Step by Step Solution

1. Step 1: Write the proportion equation
   1,255.28 : 1,731.15 = 856.76 : x
2. Step 2: Convert to fraction form
   1,255.28/1,731.15 = 856.76/x
3. Step 3: Cross multiply
   1,255.28x = 1,731.15 × 856.76
4. Step 4: Simplify right side
   1,255.28x = 1,483,171.42
5. Step 5: Solve for x
   x = 1,483,171.42/1,255.28
6. Step 6: Final answer
   x = 1,181.55