Finding the Fourth Proportional to 102.72, 142.14 and 89.82

Step by Step Solution

1. Step 1: Write the proportion equation
   102.72 : 142.14 = 89.82 : x
2. Step 2: Convert to fraction form
   102.72/142.14 = 89.82/x
3. Step 3: Cross multiply
   102.72x = 142.14 × 89.82
4. Step 4: Simplify right side
   102.72x = 12,767.01
5. Step 5: Solve for x
   x = 12,767.01/102.72
6. Step 6: Final answer
   x = 124.29