Finding the Third Proportional to 209.46 and 321.89

Step by Step Solution

1. Step 1: Write the proportion equation
   209.46 : 321.89 = 321.89 : x
2. Step 2: Convert to fraction form
   209.46/321.89 = 321.89/x
3. Step 3: Cross multiply
   209.46x = 321.89 × 321.89
4. Step 4: Simplify right side
   209.46x = 103,613.57
5. Step 5: Solve for x
   x = 103,613.57/209.46
6. Step 6: Final answer
   x = 494.67