Finding the Fourth Proportional to 142.16, 196.10 and 86.86

Step by Step Solution

1. Step 1: Write the proportion equation
   142.16 : 196.10 = 86.86 : x
2. Step 2: Convert to fraction form
   142.16/196.10 = 86.86/x
3. Step 3: Cross multiply
   142.16x = 196.10 × 86.86
4. Step 4: Simplify right side
   142.16x = 17,033.25
5. Step 5: Solve for x
   x = 17,033.25/142.16
6. Step 6: Final answer
   x = 119.82