Finding the Fourth Proportional to 142.29, 196.29 and 105.57

Step by Step Solution

1. Step 1: Write the proportion equation
   142.29 : 196.29 = 105.57 : x
2. Step 2: Convert to fraction form
   142.29/196.29 = 105.57/x
3. Step 3: Cross multiply
   142.29x = 196.29 × 105.57
4. Step 4: Simplify right side
   142.29x = 20,722.34
5. Step 5: Solve for x
   x = 20,722.34/142.29
6. Step 6: Final answer
   x = 145.63