Finding the Third Proportional to 665.72 and 1,403.89

Step by Step Solution

1. Step 1: Write the proportion equation
   665.72 : 1,403.89 = 1,403.89 : x
2. Step 2: Convert to fraction form
   665.72/1,403.89 = 1,403.89/x
3. Step 3: Cross multiply
   665.72x = 1,403.89 × 1,403.89
4. Step 4: Simplify right side
   665.72x = 1,970,919.85
5. Step 5: Solve for x
   x = 1,970,919.85/665.72
6. Step 6: Final answer
   x = 2,960.59