Finding the Fourth Proportional to 142.50, 213.78 and 51.27

Step by Step Solution

1. Step 1: Write the proportion equation
   142.50 : 213.78 = 51.27 : x
2. Step 2: Convert to fraction form
   142.50/213.78 = 51.27/x
3. Step 3: Cross multiply
   142.50x = 213.78 × 51.27
4. Step 4: Simplify right side
   142.50x = 10,960.50
5. Step 5: Solve for x
   x = 10,960.50/142.50
6. Step 6: Final answer
   x = 76.92