Finding the Fourth Proportional to 1,085.30, 1,627.54 and 856.88

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.30 : 1,627.54 = 856.88 : x
2. Step 2: Convert to fraction form
   1,085.30/1,627.54 = 856.88/x
3. Step 3: Cross multiply
   1,085.30x = 1,627.54 × 856.88
4. Step 4: Simplify right side
   1,085.30x = 1,394,606.48
5. Step 5: Solve for x
   x = 1,394,606.48/1,085.30
6. Step 6: Final answer
   x = 1,285.00