Finding the Fourth Proportional to 142.33, 213.42 and 77.31

Step by Step Solution

1. Step 1: Write the proportion equation
   142.33 : 213.42 = 77.31 : x
2. Step 2: Convert to fraction form
   142.33/213.42 = 77.31/x
3. Step 3: Cross multiply
   142.33x = 213.42 × 77.31
4. Step 4: Simplify right side
   142.33x = 16,499.50
5. Step 5: Solve for x
   x = 16,499.50/142.33
6. Step 6: Final answer
   x = 115.92