Finding the Fourth Proportional to 72.77, 109.69 and 68.78

Step by Step Solution

1. Step 1: Write the proportion equation
   72.77 : 109.69 = 68.78 : x
2. Step 2: Convert to fraction form
   72.77/109.69 = 68.78/x
3. Step 3: Cross multiply
   72.77x = 109.69 × 68.78
4. Step 4: Simplify right side
   72.77x = 7,544.58
5. Step 5: Solve for x
   x = 7,544.58/72.77
6. Step 6: Final answer
   x = 103.68