Finding the Fourth Proportional to 142.02, 196.01 and 86.79

Step by Step Solution

1. Step 1: Write the proportion equation
   142.02 : 196.01 = 86.79 : x
2. Step 2: Convert to fraction form
   142.02/196.01 = 86.79/x
3. Step 3: Cross multiply
   142.02x = 196.01 × 86.79
4. Step 4: Simplify right side
   142.02x = 17,011.27
5. Step 5: Solve for x
   x = 17,011.27/142.02
6. Step 6: Final answer
   x = 119.78