Finding the Fourth Proportional to 128.24, 192.27 and 67.31

Step by Step Solution

1. Step 1: Write the proportion equation
   128.24 : 192.27 = 67.31 : x
2. Step 2: Convert to fraction form
   128.24/192.27 = 67.31/x
3. Step 3: Cross multiply
   128.24x = 192.27 × 67.31
4. Step 4: Simplify right side
   128.24x = 12,941.69
5. Step 5: Solve for x
   x = 12,941.69/128.24
6. Step 6: Final answer
   x = 100.92