Finding the Third Proportional to 498.50 and 648

Step by Step Solution

1. Step 1: Write the proportion equation
   498.50 : 648 = 648 : x
2. Step 2: Convert to fraction form
   498.50/648 = 648/x
3. Step 3: Cross multiply
   498.50x = 648 × 648
4. Step 4: Simplify right side
   498.50x = 419,904
5. Step 5: Solve for x
   x = 419,904/498.50
6. Step 6: Final answer
   x = 842.34