Finding the Fourth Proportional to 142.37, 196.68 and 121.86

Step by Step Solution

1. Step 1: Write the proportion equation
   142.37 : 196.68 = 121.86 : x
2. Step 2: Convert to fraction form
   142.37/196.68 = 121.86/x
3. Step 3: Cross multiply
   142.37x = 196.68 × 121.86
4. Step 4: Simplify right side
   142.37x = 23,967.42
5. Step 5: Solve for x
   x = 23,967.42/142.37
6. Step 6: Final answer
   x = 168.35