Finding the Fourth Proportional to 142.11, 196.09 and 89.69

Step by Step Solution

1. Step 1: Write the proportion equation
   142.11 : 196.09 = 89.69 : x
2. Step 2: Convert to fraction form
   142.11/196.09 = 89.69/x
3. Step 3: Cross multiply
   142.11x = 196.09 × 89.69
4. Step 4: Simplify right side
   142.11x = 17,587.31
5. Step 5: Solve for x
   x = 17,587.31/142.11
6. Step 6: Final answer
   x = 123.76