Finding the Third Proportional to 229.50 and 397.69

Step by Step Solution

1. Step 1: Write the proportion equation
   229.50 : 397.69 = 397.69 : x
2. Step 2: Convert to fraction form
   229.50/397.69 = 397.69/x
3. Step 3: Cross multiply
   229.50x = 397.69 × 397.69
4. Step 4: Simplify right side
   229.50x = 158,155.35
5. Step 5: Solve for x
   x = 158,155.35/229.50
6. Step 6: Final answer
   x = 689.13