Finding the Fourth Proportional to 118.18, 163.15 and 78.89

Step by Step Solution

1. Step 1: Write the proportion equation
   118.18 : 163.15 = 78.89 : x
2. Step 2: Convert to fraction form
   118.18/163.15 = 78.89/x
3. Step 3: Cross multiply
   118.18x = 163.15 × 78.89
4. Step 4: Simplify right side
   118.18x = 12,870.90
5. Step 5: Solve for x
   x = 12,870.90/118.18
6. Step 6: Final answer
   x = 108.91