Finding the Fourth Proportional to 142.68, 196.86 and 90.96

Step by Step Solution

1. Step 1: Write the proportion equation
   142.68 : 196.86 = 90.96 : x
2. Step 2: Convert to fraction form
   142.68/196.86 = 90.96/x
3. Step 3: Cross multiply
   142.68x = 196.86 × 90.96
4. Step 4: Simplify right side
   142.68x = 17,906.39
5. Step 5: Solve for x
   x = 17,906.39/142.68
6. Step 6: Final answer
   x = 125.50