Finding the Third Proportional to 169.78 and 328.69

Step by Step Solution

1. Step 1: Write the proportion equation
   169.78 : 328.69 = 328.69 : x
2. Step 2: Convert to fraction form
   169.78/328.69 = 328.69/x
3. Step 3: Cross multiply
   169.78x = 328.69 × 328.69
4. Step 4: Simplify right side
   169.78x = 108,035.47
5. Step 5: Solve for x
   x = 108,035.47/169.78
6. Step 6: Final answer
   x = 636.32