Finding the Fourth Proportional to 105.81, 158.98 and 67.31

Step by Step Solution

1. Step 1: Write the proportion equation
   105.81 : 158.98 = 67.31 : x
2. Step 2: Convert to fraction form
   105.81/158.98 = 67.31/x
3. Step 3: Cross multiply
   105.81x = 158.98 × 67.31
4. Step 4: Simplify right side
   105.81x = 10,700.83
5. Step 5: Solve for x
   x = 10,700.83/105.81
6. Step 6: Final answer
   x = 101.13