Finding the Fourth Proportional to 117.94, 162.71 and 78.61

Step by Step Solution

1. Step 1: Write the proportion equation
   117.94 : 162.71 = 78.61 : x
2. Step 2: Convert to fraction form
   117.94/162.71 = 78.61/x
3. Step 3: Cross multiply
   117.94x = 162.71 × 78.61
4. Step 4: Simplify right side
   117.94x = 12,790.63
5. Step 5: Solve for x
   x = 12,790.63/117.94
6. Step 6: Final answer
   x = 108.45