Finding the Third Proportional to 665.50 and 916.50

Step by Step Solution

1. Step 1: Write the proportion equation
   665.50 : 916.50 = 916.50 : x
2. Step 2: Convert to fraction form
   665.50/916.50 = 916.50/x
3. Step 3: Cross multiply
   665.50x = 916.50 × 916.50
4. Step 4: Simplify right side
   665.50x = 839,972.25
5. Step 5: Solve for x
   x = 839,972.25/665.50
6. Step 6: Final answer
   x = 1,262.17