Finding the Fourth Proportional to 142.42, 196.50 and 90.68

Step by Step Solution

1. Step 1: Write the proportion equation
   142.42 : 196.50 = 90.68 : x
2. Step 2: Convert to fraction form
   142.42/196.50 = 90.68/x
3. Step 3: Cross multiply
   142.42x = 196.50 × 90.68
4. Step 4: Simplify right side
   142.42x = 17,818.62
5. Step 5: Solve for x
   x = 17,818.62/142.42
6. Step 6: Final answer
   x = 125.11