Finding the Third Proportional to 426.38 and 611.69

Step by Step Solution

1. Step 1: Write the proportion equation
   426.38 : 611.69 = 611.69 : x
2. Step 2: Convert to fraction form
   426.38/611.69 = 611.69/x
3. Step 3: Cross multiply
   426.38x = 611.69 × 611.69
4. Step 4: Simplify right side
   426.38x = 374,161.60
5. Step 5: Solve for x
   x = 374,161.60/426.38
6. Step 6: Final answer
   x = 877.54