Finding the Third Proportional to 136.69 and 287.61

Step by Step Solution

1. Step 1: Write the proportion equation
   136.69 : 287.61 = 287.61 : x
2. Step 2: Convert to fraction form
   136.69/287.61 = 287.61/x
3. Step 3: Cross multiply
   136.69x = 287.61 × 287.61
4. Step 4: Simplify right side
   136.69x = 82,721.40
5. Step 5: Solve for x
   x = 82,721.40/136.69
6. Step 6: Final answer
   x = 605.19