Finding the Fourth Proportional to 103.82, 155.50 and 78.19

Step by Step Solution

1. Step 1: Write the proportion equation
   103.82 : 155.50 = 78.19 : x
2. Step 2: Convert to fraction form
   103.82/155.50 = 78.19/x
3. Step 3: Cross multiply
   103.82x = 155.50 × 78.19
4. Step 4: Simplify right side
   103.82x = 12,158.55
5. Step 5: Solve for x
   x = 12,158.55/103.82
6. Step 6: Final answer
   x = 117.11