Finding the Fourth Proportional to 72.98, 100.55 and 57.49

Step by Step Solution

1. Step 1: Write the proportion equation
   72.98 : 100.55 = 57.49 : x
2. Step 2: Convert to fraction form
   72.98/100.55 = 57.49/x
3. Step 3: Cross multiply
   72.98x = 100.55 × 57.49
4. Step 4: Simplify right side
   72.98x = 5,780.62
5. Step 5: Solve for x
   x = 5,780.62/72.98
6. Step 6: Final answer
   x = 79.21