Finding the Fourth Proportional to 142.65, 196.79 and 121.05

Step by Step Solution

1. Step 1: Write the proportion equation
   142.65 : 196.79 = 121.05 : x
2. Step 2: Convert to fraction form
   142.65/196.79 = 121.05/x
3. Step 3: Cross multiply
   142.65x = 196.79 × 121.05
4. Step 4: Simplify right side
   142.65x = 23,820.82
5. Step 5: Solve for x
   x = 23,820.82/142.65
6. Step 6: Final answer
   x = 166.99