Finding the Fourth Proportional to 72.72, 108.38 and 68.78

Step by Step Solution

1. Step 1: Write the proportion equation
   72.72 : 108.38 = 68.78 : x
2. Step 2: Convert to fraction form
   72.72/108.38 = 68.78/x
3. Step 3: Cross multiply
   72.72x = 108.38 × 68.78
4. Step 4: Simplify right side
   72.72x = 7,454.38
5. Step 5: Solve for x
   x = 7,454.38/72.72
6. Step 6: Final answer
   x = 102.51