Finding the Fourth Proportional to 1,079.55, 1,489.94 and 660.15

Step by Step Solution

1. Step 1: Write the proportion equation
   1,079.55 : 1,489.94 = 660.15 : x
2. Step 2: Convert to fraction form
   1,079.55/1,489.94 = 660.15/x
3. Step 3: Cross multiply
   1,079.55x = 1,489.94 × 660.15
4. Step 4: Simplify right side
   1,079.55x = 983,583.89
5. Step 5: Solve for x
   x = 983,583.89/1,079.55
6. Step 6: Final answer
   x = 911.11