Finding the Third Proportional to 401.25 and 620.25

Step by Step Solution

1. Step 1: Write the proportion equation
   401.25 : 620.25 = 620.25 : x
2. Step 2: Convert to fraction form
   401.25/620.25 = 620.25/x
3. Step 3: Cross multiply
   401.25x = 620.25 × 620.25
4. Step 4: Simplify right side
   401.25x = 384,710.06
5. Step 5: Solve for x
   x = 384,710.06/401.25
6. Step 6: Final answer
   x = 958.78