Finding the Fourth Proportional to 72.21, 108.72 and 54.33

Step by Step Solution

1. Step 1: Write the proportion equation
   72.21 : 108.72 = 54.33 : x
2. Step 2: Convert to fraction form
   72.21/108.72 = 54.33/x
3. Step 3: Cross multiply
   72.21x = 108.72 × 54.33
4. Step 4: Simplify right side
   72.21x = 5,906.76
5. Step 5: Solve for x
   x = 5,906.76/72.21
6. Step 6: Final answer
   x = 81.80