Finding the Fourth Proportional to 72.49, 108.78 and 40.42

Step by Step Solution

1. Step 1: Write the proportion equation
   72.49 : 108.78 = 40.42 : x
2. Step 2: Convert to fraction form
   72.49/108.78 = 40.42/x
3. Step 3: Cross multiply
   72.49x = 108.78 × 40.42
4. Step 4: Simplify right side
   72.49x = 4,396.89
5. Step 5: Solve for x
   x = 4,396.89/72.49
6. Step 6: Final answer
   x = 60.66