Finding the Third Proportional to 129.75 and 196.78

Step by Step Solution

1. Step 1: Write the proportion equation
   129.75 : 196.78 = 196.78 : x
2. Step 2: Convert to fraction form
   129.75/196.78 = 196.78/x
3. Step 3: Cross multiply
   129.75x = 196.78 × 196.78
4. Step 4: Simplify right side
   129.75x = 38,722.86
5. Step 5: Solve for x
   x = 38,722.86/129.75
6. Step 6: Final answer
   x = 298.44