Finding the Third Proportional to 154.31 and 321.38

Step by Step Solution

1. Step 1: Write the proportion equation
   154.31 : 321.38 = 321.38 : x
2. Step 2: Convert to fraction form
   154.31/321.38 = 321.38/x
3. Step 3: Cross multiply
   154.31x = 321.38 × 321.38
4. Step 4: Simplify right side
   154.31x = 103,281.89
5. Step 5: Solve for x
   x = 103,281.89/154.31
6. Step 6: Final answer
   x = 669.30