Finding the Fourth Proportional to 1,085.28, 1,497.72 and 613.20

Step by Step Solution

1. Step 1: Write the proportion equation
   1,085.28 : 1,497.72 = 613.20 : x
2. Step 2: Convert to fraction form
   1,085.28/1,497.72 = 613.20/x
3. Step 3: Cross multiply
   1,085.28x = 1,497.72 × 613.20
4. Step 4: Simplify right side
   1,085.28x = 918,401.90
5. Step 5: Solve for x
   x = 918,401.90/1,085.28
6. Step 6: Final answer
   x = 846.23