Finding the Third Proportional to 318.94 and 488.53

Step by Step Solution

1. Step 1: Write the proportion equation
   318.94 : 488.53 = 488.53 : x
2. Step 2: Convert to fraction form
   318.94/488.53 = 488.53/x
3. Step 3: Cross multiply
   318.94x = 488.53 × 488.53
4. Step 4: Simplify right side
   318.94x = 238,662.78
5. Step 5: Solve for x
   x = 238,662.78/318.94
6. Step 6: Final answer
   x = 748.31