Finding the Third Proportional to 388 and 501.50

Step by Step Solution

1. Step 1: Write the proportion equation
   388 : 501.50 = 501.50 : x
2. Step 2: Convert to fraction form
   388/501.50 = 501.50/x
3. Step 3: Cross multiply
   388x = 501.50 × 501.50
4. Step 4: Simplify right side
   388x = 251,502.25
5. Step 5: Solve for x
   x = 251,502.25/388
6. Step 6: Final answer
   x = 648.20