Finding the Fourth Proportional to 1,152.54, 1,728.72 and 665.28

Step by Step Solution

1. Step 1: Write the proportion equation
   1,152.54 : 1,728.72 = 665.28 : x
2. Step 2: Convert to fraction form
   1,152.54/1,728.72 = 665.28/x
3. Step 3: Cross multiply
   1,152.54x = 1,728.72 × 665.28
4. Step 4: Simplify right side
   1,152.54x = 1,150,082.84
5. Step 5: Solve for x
   x = 1,150,082.84/1,152.54
6. Step 6: Final answer
   x = 997.87