Finding the Fourth Proportional to 142.56, 213.57 and 96.78

Step by Step Solution

1. Step 1: Write the proportion equation
   142.56 : 213.57 = 96.78 : x
2. Step 2: Convert to fraction form
   142.56/213.57 = 96.78/x
3. Step 3: Cross multiply
   142.56x = 213.57 × 96.78
4. Step 4: Simplify right side
   142.56x = 20,669.30
5. Step 5: Solve for x
   x = 20,669.30/142.56
6. Step 6: Final answer
   x = 144.99