Finding the Fourth Proportional to 72.96, 100.71 and 55.50

Step by Step Solution

1. Step 1: Write the proportion equation
   72.96 : 100.71 = 55.50 : x
2. Step 2: Convert to fraction form
   72.96/100.71 = 55.50/x
3. Step 3: Cross multiply
   72.96x = 100.71 × 55.50
4. Step 4: Simplify right side
   72.96x = 5,589.41
5. Step 5: Solve for x
   x = 5,589.41/72.96
6. Step 6: Final answer
   x = 76.61