Finding the Third Proportional to 122.45 and 288.56

Step by Step Solution

1. Step 1: Write the proportion equation
   122.45 : 288.56 = 288.56 : x
2. Step 2: Convert to fraction form
   122.45/288.56 = 288.56/x
3. Step 3: Cross multiply
   122.45x = 288.56 × 288.56
4. Step 4: Simplify right side
   122.45x = 83,268.32
5. Step 5: Solve for x
   x = 83,268.32/122.45
6. Step 6: Final answer
   x = 680.02