Finding the Third Proportional to 137.50 and 212.50

Step by Step Solution

1. Step 1: Write the proportion equation
   137.50 : 212.50 = 212.50 : x
2. Step 2: Convert to fraction form
   137.50/212.50 = 212.50/x
3. Step 3: Cross multiply
   137.50x = 212.50 × 212.50
4. Step 4: Simplify right side
   137.50x = 45,156.25
5. Step 5: Solve for x
   x = 45,156.25/137.50
6. Step 6: Final answer
   x = 328.41