Finding the Fourth Proportional to 105.75, 158.49 and 78.48

Step by Step Solution

1. Step 1: Write the proportion equation
   105.75 : 158.49 = 78.48 : x
2. Step 2: Convert to fraction form
   105.75/158.49 = 78.48/x
3. Step 3: Cross multiply
   105.75x = 158.49 × 78.48
4. Step 4: Simplify right side
   105.75x = 12,438.30
5. Step 5: Solve for x
   x = 12,438.30/105.75
6. Step 6: Final answer
   x = 117.62