Finding the Third Proportional to 268.69 and 415.69

Step by Step Solution

1. Step 1: Write the proportion equation
   268.69 : 415.69 = 415.69 : x
2. Step 2: Convert to fraction form
   268.69/415.69 = 415.69/x
3. Step 3: Cross multiply
   268.69x = 415.69 × 415.69
4. Step 4: Simplify right side
   268.69x = 172,796.10
5. Step 5: Solve for x
   x = 172,796.10/268.69
6. Step 6: Final answer
   x = 643.11