Finding the Third Proportional to 252.50 and 404.50

Step by Step Solution

1. Step 1: Write the proportion equation
   252.50 : 404.50 = 404.50 : x
2. Step 2: Convert to fraction form
   252.50/404.50 = 404.50/x
3. Step 3: Cross multiply
   252.50x = 404.50 × 404.50
4. Step 4: Simplify right side
   252.50x = 163,620.25
5. Step 5: Solve for x
   x = 163,620.25/252.50
6. Step 6: Final answer
   x = 648.00