Finding the Fourth Proportional to 72.98, 109.43 and 38.78

Step by Step Solution

1. Step 1: Write the proportion equation
   72.98 : 109.43 = 38.78 : x
2. Step 2: Convert to fraction form
   72.98/109.43 = 38.78/x
3. Step 3: Cross multiply
   72.98x = 109.43 × 38.78
4. Step 4: Simplify right side
   72.98x = 4,243.73
5. Step 5: Solve for x
   x = 4,243.73/72.98
6. Step 6: Final answer
   x = 58.15