Finding the Third Proportional to 665.72 and 1,003.64

Step by Step Solution

1. Step 1: Write the proportion equation
   665.72 : 1,003.64 = 1,003.64 : x
2. Step 2: Convert to fraction form
   665.72/1,003.64 = 1,003.64/x
3. Step 3: Cross multiply
   665.72x = 1,003.64 × 1,003.64
4. Step 4: Simplify right side
   665.72x = 1,007,294.50
5. Step 5: Solve for x
   x = 1,007,294.50/665.72
6. Step 6: Final answer
   x = 1,513.09