Finding the Third Proportional to 129.94 and 206.72

Step by Step Solution

1. Step 1: Write the proportion equation
   129.94 : 206.72 = 206.72 : x
2. Step 2: Convert to fraction form
   129.94/206.72 = 206.72/x
3. Step 3: Cross multiply
   129.94x = 206.72 × 206.72
4. Step 4: Simplify right side
   129.94x = 42,732.64
5. Step 5: Solve for x
   x = 42,732.64/129.94
6. Step 6: Final answer
   x = 328.87