Finding the Fourth Proportional to 72.72, 109.15 and 54.79

Step by Step Solution

1. Step 1: Write the proportion equation
   72.72 : 109.15 = 54.79 : x
2. Step 2: Convert to fraction form
   72.72/109.15 = 54.79/x
3. Step 3: Cross multiply
   72.72x = 109.15 × 54.79
4. Step 4: Simplify right side
   72.72x = 5,980.33
5. Step 5: Solve for x
   x = 5,980.33/72.72
6. Step 6: Final answer
   x = 82.24