Finding the Third Proportional to 396.69 and 571.69

Step by Step Solution

1. Step 1: Write the proportion equation
   396.69 : 571.69 = 571.69 : x
2. Step 2: Convert to fraction form
   396.69/571.69 = 571.69/x
3. Step 3: Cross multiply
   396.69x = 571.69 × 571.69
4. Step 4: Simplify right side
   396.69x = 326,826.60
5. Step 5: Solve for x
   x = 326,826.60/396.69
6. Step 6: Final answer
   x = 823.89