Finding the Fourth Proportional to 142.88, 214.27 and 50.31

Step by Step Solution

1. Step 1: Write the proportion equation
   142.88 : 214.27 = 50.31 : x
2. Step 2: Convert to fraction form
   142.88/214.27 = 50.31/x
3. Step 3: Cross multiply
   142.88x = 214.27 × 50.31
4. Step 4: Simplify right side
   142.88x = 10,779.72
5. Step 5: Solve for x
   x = 10,779.72/142.88
6. Step 6: Final answer
   x = 75.45