Finding the Third Proportional to 139.50 and 213.75

Step by Step Solution

1. Step 1: Write the proportion equation
   139.50 : 213.75 = 213.75 : x
2. Step 2: Convert to fraction form
   139.50/213.75 = 213.75/x
3. Step 3: Cross multiply
   139.50x = 213.75 × 213.75
4. Step 4: Simplify right side
   139.50x = 45,689.06
5. Step 5: Solve for x
   x = 45,689.06/139.50
6. Step 6: Final answer
   x = 327.52