Finding the Third Proportional to 660.56 and 989.02

Step by Step Solution

1. Step 1: Write the proportion equation
   660.56 : 989.02 = 989.02 : x
2. Step 2: Convert to fraction form
   660.56/989.02 = 989.02/x
3. Step 3: Cross multiply
   660.56x = 989.02 × 989.02
4. Step 4: Simplify right side
   660.56x = 978,151.91
5. Step 5: Solve for x
   x = 978,151.91/660.56
6. Step 6: Final answer
   x = 1,480.79