Finding the Third Proportional to 400 and 522.50

Step by Step Solution

1. Step 1: Write the proportion equation
   400 : 522.50 = 522.50 : x
2. Step 2: Convert to fraction form
   400/522.50 = 522.50/x
3. Step 3: Cross multiply
   400x = 522.50 × 522.50
4. Step 4: Simplify right side
   400x = 273,006.25
5. Step 5: Solve for x
   x = 273,006.25/400
6. Step 6: Final answer
   x = 682.52