Finding the Fourth Proportional to 105.67, 158.23 and 78.49

Step by Step Solution

1. Step 1: Write the proportion equation
   105.67 : 158.23 = 78.49 : x
2. Step 2: Convert to fraction form
   105.67/158.23 = 78.49/x
3. Step 3: Cross multiply
   105.67x = 158.23 × 78.49
4. Step 4: Simplify right side
   105.67x = 12,419.47
5. Step 5: Solve for x
   x = 12,419.47/105.67
6. Step 6: Final answer
   x = 117.53