Finding the Fourth Proportional to 105.48, 158.00 and 78.66

Step by Step Solution

1. Step 1: Write the proportion equation
   105.48 : 158.00 = 78.66 : x
2. Step 2: Convert to fraction form
   105.48/158.00 = 78.66/x
3. Step 3: Cross multiply
   105.48x = 158.00 × 78.66
4. Step 4: Simplify right side
   105.48x = 12,427.89
5. Step 5: Solve for x
   x = 12,427.89/105.48
6. Step 6: Final answer
   x = 117.82