Finding the Fourth Proportional to 80.69, 111.28 and 53.09

Step by Step Solution

1. Step 1: Write the proportion equation
   80.69 : 111.28 = 53.09 : x
2. Step 2: Convert to fraction form
   80.69/111.28 = 53.09/x
3. Step 3: Cross multiply
   80.69x = 111.28 × 53.09
4. Step 4: Simplify right side
   80.69x = 5,907.17
5. Step 5: Solve for x
   x = 5,907.17/80.69
6. Step 6: Final answer
   x = 73.21