Finding the Third Proportional to 261.69 and 392.56

Step by Step Solution

1. Step 1: Write the proportion equation
   261.69 : 392.56 = 392.56 : x
2. Step 2: Convert to fraction form
   261.69/392.56 = 392.56/x
3. Step 3: Cross multiply
   261.69x = 392.56 × 392.56
4. Step 4: Simplify right side
   261.69x = 154,105.32
5. Step 5: Solve for x
   x = 154,105.32/261.69
6. Step 6: Final answer
   x = 588.89