Finding the Fourth Proportional to 142.72, 196.76 and 90.96

Step by Step Solution

1. Step 1: Write the proportion equation
   142.72 : 196.76 = 90.96 : x
2. Step 2: Convert to fraction form
   142.72/196.76 = 90.96/x
3. Step 3: Cross multiply
   142.72x = 196.76 × 90.96
4. Step 4: Simplify right side
   142.72x = 17,897.29
5. Step 5: Solve for x
   x = 17,897.29/142.72
6. Step 6: Final answer
   x = 125.40