Finding the Third Proportional to 288.56 and 622.69

Step by Step Solution

1. Step 1: Write the proportion equation
   288.56 : 622.69 = 622.69 : x
2. Step 2: Convert to fraction form
   288.56/622.69 = 622.69/x
3. Step 3: Cross multiply
   288.56x = 622.69 × 622.69
4. Step 4: Simplify right side
   288.56x = 387,739.72
5. Step 5: Solve for x
   x = 387,739.72/288.56
6. Step 6: Final answer
   x = 1,343.69