Finding the Fourth Proportional to 142.62, 196.71 and 121.98

Step by Step Solution

1. Step 1: Write the proportion equation
   142.62 : 196.71 = 121.98 : x
2. Step 2: Convert to fraction form
   142.62/196.71 = 121.98/x
3. Step 3: Cross multiply
   142.62x = 196.71 × 121.98
4. Step 4: Simplify right side
   142.62x = 23,994.69
5. Step 5: Solve for x
   x = 23,994.69/142.62
6. Step 6: Final answer
   x = 168.24