Finding the Fourth Proportional to 142.14, 196.17 and 83.91

Step by Step Solution

1. Step 1: Write the proportion equation
   142.14 : 196.17 = 83.91 : x
2. Step 2: Convert to fraction form
   142.14/196.17 = 83.91/x
3. Step 3: Cross multiply
   142.14x = 196.17 × 83.91
4. Step 4: Simplify right side
   142.14x = 16,460.62
5. Step 5: Solve for x
   x = 16,460.62/142.14
6. Step 6: Final answer
   x = 115.81