Finding the Fourth Proportional to 103.96, 155.78 and 69.78

Step by Step Solution

1. Step 1: Write the proportion equation
   103.96 : 155.78 = 69.78 : x
2. Step 2: Convert to fraction form
   103.96/155.78 = 69.78/x
3. Step 3: Cross multiply
   103.96x = 155.78 × 69.78
4. Step 4: Simplify right side
   103.96x = 10,870.33
5. Step 5: Solve for x
   x = 10,870.33/103.96
6. Step 6: Final answer
   x = 104.56