Finding the Fourth Proportional to 1,485.20, 2,049.52 and 855.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,485.20 : 2,049.52 = 855.60 : x
2. Step 2: Convert to fraction form
   1,485.20/2,049.52 = 855.60/x
3. Step 3: Cross multiply
   1,485.20x = 2,049.52 × 855.60
4. Step 4: Simplify right side
   1,485.20x = 1,753,569.31
5. Step 5: Solve for x
   x = 1,753,569.31/1,485.20
6. Step 6: Final answer
   x = 1,180.70