Finding the Third Proportional to 411.75 and 637.69

Step by Step Solution

1. Step 1: Write the proportion equation
   411.75 : 637.69 = 637.69 : x
2. Step 2: Convert to fraction form
   411.75/637.69 = 637.69/x
3. Step 3: Cross multiply
   411.75x = 637.69 × 637.69
4. Step 4: Simplify right side
   411.75x = 406,645.35
5. Step 5: Solve for x
   x = 406,645.35/411.75
6. Step 6: Final answer
   x = 987.60