Finding the Fourth Proportional to 142.28, 196.38 and 90.50

Step by Step Solution

1. Step 1: Write the proportion equation
   142.28 : 196.38 = 90.50 : x
2. Step 2: Convert to fraction form
   142.28/196.38 = 90.50/x
3. Step 3: Cross multiply
   142.28x = 196.38 × 90.50
4. Step 4: Simplify right side
   142.28x = 17,772.39
5. Step 5: Solve for x
   x = 17,772.39/142.28
6. Step 6: Final answer
   x = 124.91