Finding the Fourth Proportional to 117.72, 162.52 and 78.38

Step by Step Solution

1. Step 1: Write the proportion equation
   117.72 : 162.52 = 78.38 : x
2. Step 2: Convert to fraction form
   117.72/162.52 = 78.38/x
3. Step 3: Cross multiply
   117.72x = 162.52 × 78.38
4. Step 4: Simplify right side
   117.72x = 12,738.32
5. Step 5: Solve for x
   x = 12,738.32/117.72
6. Step 6: Final answer
   x = 108.21