Finding the Fourth Proportional to 117.79, 162.50 and 78.49

Step by Step Solution

1. Step 1: Write the proportion equation
   117.79 : 162.50 = 78.49 : x
2. Step 2: Convert to fraction form
   117.79/162.50 = 78.49/x
3. Step 3: Cross multiply
   117.79x = 162.50 × 78.49
4. Step 4: Simplify right side
   117.79x = 12,753.83
5. Step 5: Solve for x
   x = 12,753.83/117.79
6. Step 6: Final answer
   x = 108.28