Finding the Fourth Proportional to 117.72, 162.18 and 78.84

Step by Step Solution

1. Step 1: Write the proportion equation
   117.72 : 162.18 = 78.84 : x
2. Step 2: Convert to fraction form
   117.72/162.18 = 78.84/x
3. Step 3: Cross multiply
   117.72x = 162.18 × 78.84
4. Step 4: Simplify right side
   117.72x = 12,786.27
5. Step 5: Solve for x
   x = 12,786.27/117.72
6. Step 6: Final answer
   x = 108.62