Finding the Third Proportional to 400.69 and 520.56

Step by Step Solution

1. Step 1: Write the proportion equation
   400.69 : 520.56 = 520.56 : x
2. Step 2: Convert to fraction form
   400.69/520.56 = 520.56/x
3. Step 3: Cross multiply
   400.69x = 520.56 × 520.56
4. Step 4: Simplify right side
   400.69x = 270,985.32
5. Step 5: Solve for x
   x = 270,985.32/400.69
6. Step 6: Final answer
   x = 676.30