Finding the Fourth Proportional to 1,079.64, 1,489.89 and 660.72

Step by Step Solution

1. Step 1: Write the proportion equation
   1,079.64 : 1,489.89 = 660.72 : x
2. Step 2: Convert to fraction form
   1,079.64/1,489.89 = 660.72/x
3. Step 3: Cross multiply
   1,079.64x = 1,489.89 × 660.72
4. Step 4: Simplify right side
   1,079.64x = 984,400.12
5. Step 5: Solve for x
   x = 984,400.12/1,079.64
6. Step 6: Final answer
   x = 911.79