Finding the Third Proportional to 153.25 and 221.38

Step by Step Solution

1. Step 1: Write the proportion equation
   153.25 : 221.38 = 221.38 : x
2. Step 2: Convert to fraction form
   153.25/221.38 = 221.38/x
3. Step 3: Cross multiply
   153.25x = 221.38 × 221.38
4. Step 4: Simplify right side
   153.25x = 49,006.89
5. Step 5: Solve for x
   x = 49,006.89/153.25
6. Step 6: Final answer
   x = 319.78