Finding the Third Proportional to 238.50 and 398.25

Step by Step Solution

1. Step 1: Write the proportion equation
   238.50 : 398.25 = 398.25 : x
2. Step 2: Convert to fraction form
   238.50/398.25 = 398.25/x
3. Step 3: Cross multiply
   238.50x = 398.25 × 398.25
4. Step 4: Simplify right side
   238.50x = 158,603.06
5. Step 5: Solve for x
   x = 158,603.06/238.50
6. Step 6: Final answer
   x = 665.00