Finding the Third Proportional to 287.81 and 624.56

Step by Step Solution

1. Step 1: Write the proportion equation
   287.81 : 624.56 = 624.56 : x
2. Step 2: Convert to fraction form
   287.81/624.56 = 624.56/x
3. Step 3: Cross multiply
   287.81x = 624.56 × 624.56
4. Step 4: Simplify right side
   287.81x = 390,078.32
5. Step 5: Solve for x
   x = 390,078.32/287.81
6. Step 6: Final answer
   x = 1,355.32