Finding the Fourth Proportional to 142.24, 196.31 and 100.88

Step by Step Solution

1. Step 1: Write the proportion equation
   142.24 : 196.31 = 100.88 : x
2. Step 2: Convert to fraction form
   142.24/196.31 = 100.88/x
3. Step 3: Cross multiply
   142.24x = 196.31 × 100.88
4. Step 4: Simplify right side
   142.24x = 19,803.19
5. Step 5: Solve for x
   x = 19,803.19/142.24
6. Step 6: Final answer
   x = 139.22