Finding the Third Proportional to 138.66 and 329.72

Step by Step Solution

1. Step 1: Write the proportion equation
   138.66 : 329.72 = 329.72 : x
2. Step 2: Convert to fraction form
   138.66/329.72 = 329.72/x
3. Step 3: Cross multiply
   138.66x = 329.72 × 329.72
4. Step 4: Simplify right side
   138.66x = 108,714.45
5. Step 5: Solve for x
   x = 108,714.45/138.66
6. Step 6: Final answer
   x = 784.06