Finding the Third Proportional to 121.50 and 216.25

Step by Step Solution

1. Step 1: Write the proportion equation
   121.50 : 216.25 = 216.25 : x
2. Step 2: Convert to fraction form
   121.50/216.25 = 216.25/x
3. Step 3: Cross multiply
   121.50x = 216.25 × 216.25
4. Step 4: Simplify right side
   121.50x = 46,764.06
5. Step 5: Solve for x
   x = 46,764.06/121.50
6. Step 6: Final answer
   x = 384.89