Finding the Fourth Proportional to 105.65, 158.33 and 78.62

Step by Step Solution

1. Step 1: Write the proportion equation
   105.65 : 158.33 = 78.62 : x
2. Step 2: Convert to fraction form
   105.65/158.33 = 78.62/x
3. Step 3: Cross multiply
   105.65x = 158.33 × 78.62
4. Step 4: Simplify right side
   105.65x = 12,447.98
5. Step 5: Solve for x
   x = 12,447.98/105.65
6. Step 6: Final answer
   x = 117.82