Finding the Third Proportional to 401.34 and 621.28

Step by Step Solution

1. Step 1: Write the proportion equation
   401.34 : 621.28 = 621.28 : x
2. Step 2: Convert to fraction form
   401.34/621.28 = 621.28/x
3. Step 3: Cross multiply
   401.34x = 621.28 × 621.28
4. Step 4: Simplify right side
   401.34x = 385,990.39
5. Step 5: Solve for x
   x = 385,990.39/401.34
6. Step 6: Final answer
   x = 961.75