Finding the Fourth Proportional to 72.98, 100.88 and 55.58

Step by Step Solution

1. Step 1: Write the proportion equation
   72.98 : 100.88 = 55.58 : x
2. Step 2: Convert to fraction form
   72.98/100.88 = 55.58/x
3. Step 3: Cross multiply
   72.98x = 100.88 × 55.58
4. Step 4: Simplify right side
   72.98x = 5,606.54
5. Step 5: Solve for x
   x = 5,606.54/72.98
6. Step 6: Final answer
   x = 76.83