Finding the Third Proportional to 76.78 and 105.47

Step by Step Solution

1. Step 1: Write the proportion equation
   76.78 : 105.47 = 105.47 : x
2. Step 2: Convert to fraction form
   76.78/105.47 = 105.47/x
3. Step 3: Cross multiply
   76.78x = 105.47 × 105.47
4. Step 4: Simplify right side
   76.78x = 11,123.66
5. Step 5: Solve for x
   x = 11,123.66/76.78
6. Step 6: Final answer
   x = 144.87