Finding the Fourth Proportional to 80.72, 111.33 and 53.09

Step by Step Solution

1. Step 1: Write the proportion equation
   80.72 : 111.33 = 53.09 : x
2. Step 2: Convert to fraction form
   80.72/111.33 = 53.09/x
3. Step 3: Cross multiply
   80.72x = 111.33 × 53.09
4. Step 4: Simplify right side
   80.72x = 5,909.95
5. Step 5: Solve for x
   x = 5,909.95/80.72
6. Step 6: Final answer
   x = 73.22