Finding the Third Proportional to 77.79 and 105.57

Step by Step Solution

1. Step 1: Write the proportion equation
   77.79 : 105.57 = 105.57 : x
2. Step 2: Convert to fraction form
   77.79/105.57 = 105.57/x
3. Step 3: Cross multiply
   77.79x = 105.57 × 105.57
4. Step 4: Simplify right side
   77.79x = 11,144.83
5. Step 5: Solve for x
   x = 11,144.83/77.79
6. Step 6: Final answer
   x = 143.27