Finding the Fourth Proportional to 105.36, 158.10 and 78.37

Step by Step Solution

1. Step 1: Write the proportion equation
   105.36 : 158.10 = 78.37 : x
2. Step 2: Convert to fraction form
   105.36/158.10 = 78.37/x
3. Step 3: Cross multiply
   105.36x = 158.10 × 78.37
4. Step 4: Simplify right side
   105.36x = 12,390.05
5. Step 5: Solve for x
   x = 12,390.05/105.36
6. Step 6: Final answer
   x = 117.59