Finding the Third Proportional to 406.90 and 624.59

Step by Step Solution

1. Step 1: Write the proportion equation
   406.90 : 624.59 = 624.59 : x
2. Step 2: Convert to fraction form
   406.90/624.59 = 624.59/x
3. Step 3: Cross multiply
   406.90x = 624.59 × 624.59
4. Step 4: Simplify right side
   406.90x = 390,107.59
5. Step 5: Solve for x
   x = 390,107.59/406.90
6. Step 6: Final answer
   x = 958.73