Finding the Fourth Proportional to 142.48, 196.72 and 90.80

Step by Step Solution

1. Step 1: Write the proportion equation
   142.48 : 196.72 = 90.80 : x
2. Step 2: Convert to fraction form
   142.48/196.72 = 90.80/x
3. Step 3: Cross multiply
   142.48x = 196.72 × 90.80
4. Step 4: Simplify right side
   142.48x = 17,862.18
5. Step 5: Solve for x
   x = 17,862.18/142.48
6. Step 6: Final answer
   x = 125.37