Finding the Fourth Proportional to 142.72, 213.72 and 97.15

Step by Step Solution

1. Step 1: Write the proportion equation
   142.72 : 213.72 = 97.15 : x
2. Step 2: Convert to fraction form
   142.72/213.72 = 97.15/x
3. Step 3: Cross multiply
   142.72x = 213.72 × 97.15
4. Step 4: Simplify right side
   142.72x = 20,762.90
5. Step 5: Solve for x
   x = 20,762.90/142.72
6. Step 6: Final answer
   x = 145.48