Finding the Fourth Proportional to 142.78, 214.25 and 142.32

Step by Step Solution

1. Step 1: Write the proportion equation
   142.78 : 214.25 = 142.32 : x
2. Step 2: Convert to fraction form
   142.78/214.25 = 142.32/x
3. Step 3: Cross multiply
   142.78x = 214.25 × 142.32
4. Step 4: Simplify right side
   142.78x = 30,492.15
5. Step 5: Solve for x
   x = 30,492.15/142.78
6. Step 6: Final answer
   x = 213.56