Finding the Third Proportional to 81.94 and 142.78

Step by Step Solution

1. Step 1: Write the proportion equation
   81.94 : 142.78 = 142.78 : x
2. Step 2: Convert to fraction form
   81.94/142.78 = 142.78/x
3. Step 3: Cross multiply
   81.94x = 142.78 × 142.78
4. Step 4: Simplify right side
   81.94x = 20,386.49
5. Step 5: Solve for x
   x = 20,386.49/81.94
6. Step 6: Final answer
   x = 248.81