Finding the Third Proportional to 123.19 and 208.69

Step by Step Solution

1. Step 1: Write the proportion equation
   123.19 : 208.69 = 208.69 : x
2. Step 2: Convert to fraction form
   123.19/208.69 = 208.69/x
3. Step 3: Cross multiply
   123.19x = 208.69 × 208.69
4. Step 4: Simplify right side
   123.19x = 43,550.47
5. Step 5: Solve for x
   x = 43,550.47/123.19
6. Step 6: Final answer
   x = 353.53