Finding the Fourth Proportional to 1,066.56, 1,601.28 and 489.60

Step by Step Solution

1. Step 1: Write the proportion equation
   1,066.56 : 1,601.28 = 489.60 : x
2. Step 2: Convert to fraction form
   1,066.56/1,601.28 = 489.60/x
3. Step 3: Cross multiply
   1,066.56x = 1,601.28 × 489.60
4. Step 4: Simplify right side
   1,066.56x = 783,986.69
5. Step 5: Solve for x
   x = 783,986.69/1,066.56
6. Step 6: Final answer
   x = 735.06