Finding the Fourth Proportional to 105.78, 158.52 and 67.14

Step by Step Solution

1. Step 1: Write the proportion equation
   105.78 : 158.52 = 67.14 : x
2. Step 2: Convert to fraction form
   105.78/158.52 = 67.14/x
3. Step 3: Cross multiply
   105.78x = 158.52 × 67.14
4. Step 4: Simplify right side
   105.78x = 10,643.03
5. Step 5: Solve for x
   x = 10,643.03/105.78
6. Step 6: Final answer
   x = 100.61