Finding the Fourth Proportional to 142.25, 196.31 and 86.98

Step by Step Solution

1. Step 1: Write the proportion equation
   142.25 : 196.31 = 86.98 : x
2. Step 2: Convert to fraction form
   142.25/196.31 = 86.98/x
3. Step 3: Cross multiply
   142.25x = 196.31 × 86.98
4. Step 4: Simplify right side
   142.25x = 17,074.61
5. Step 5: Solve for x
   x = 17,074.61/142.25
6. Step 6: Final answer
   x = 120.03