Finding the Third Proportional to 491.38 and 622.69

Step by Step Solution

1. Step 1: Write the proportion equation
   491.38 : 622.69 = 622.69 : x
2. Step 2: Convert to fraction form
   491.38/622.69 = 622.69/x
3. Step 3: Cross multiply
   491.38x = 622.69 × 622.69
4. Step 4: Simplify right side
   491.38x = 387,739.72
5. Step 5: Solve for x
   x = 387,739.72/491.38
6. Step 6: Final answer
   x = 789.09