Finding the Fourth Proportional to 102.69, 141.57 and 80.82

Step by Step Solution

1. Step 1: Write the proportion equation
   102.69 : 141.57 = 80.82 : x
2. Step 2: Convert to fraction form
   102.69/141.57 = 80.82/x
3. Step 3: Cross multiply
   102.69x = 141.57 × 80.82
4. Step 4: Simplify right side
   102.69x = 11,441.69
5. Step 5: Solve for x
   x = 11,441.69/102.69
6. Step 6: Final answer
   x = 111.42