Finding the Third Proportional to 426.56 and 697.69

Step by Step Solution

1. Step 1: Write the proportion equation
   426.56 : 697.69 = 697.69 : x
2. Step 2: Convert to fraction form
   426.56/697.69 = 697.69/x
3. Step 3: Cross multiply
   426.56x = 697.69 × 697.69
4. Step 4: Simplify right side
   426.56x = 486,767.85
5. Step 5: Solve for x
   x = 486,767.85/426.56
6. Step 6: Final answer
   x = 1,141.14