Finding the Fourth Proportional to 142.24, 196.32 and 98.72

Step by Step Solution

1. Step 1: Write the proportion equation
   142.24 : 196.32 = 98.72 : x
2. Step 2: Convert to fraction form
   142.24/196.32 = 98.72/x
3. Step 3: Cross multiply
   142.24x = 196.32 × 98.72
4. Step 4: Simplify right side
   142.24x = 19,380.71
5. Step 5: Solve for x
   x = 19,380.71/142.24
6. Step 6: Final answer
   x = 136.25