Finding the Third Proportional to 439.50 and 661.88

Step by Step Solution

1. Step 1: Write the proportion equation
   439.50 : 661.88 = 661.88 : x
2. Step 2: Convert to fraction form
   439.50/661.88 = 661.88/x
3. Step 3: Cross multiply
   439.50x = 661.88 × 661.88
4. Step 4: Simplify right side
   439.50x = 438,078.52
5. Step 5: Solve for x
   x = 438,078.52/439.50
6. Step 6: Final answer
   x = 996.77