Finding the Fourth Proportional to 142.14, 196.16 and 86.86

Step by Step Solution

1. Step 1: Write the proportion equation
   142.14 : 196.16 = 86.86 : x
2. Step 2: Convert to fraction form
   142.14/196.16 = 86.86/x
3. Step 3: Cross multiply
   142.14x = 196.16 × 86.86
4. Step 4: Simplify right side
   142.14x = 17,038.59
5. Step 5: Solve for x
   x = 17,038.59/142.14
6. Step 6: Final answer
   x = 119.88