Finding the Fourth Proportional to 80.83, 111.59 and 78.55

Step by Step Solution

1. Step 1: Write the proportion equation
   80.83 : 111.59 = 78.55 : x
2. Step 2: Convert to fraction form
   80.83/111.59 = 78.55/x
3. Step 3: Cross multiply
   80.83x = 111.59 × 78.55
4. Step 4: Simplify right side
   80.83x = 8,765.00
5. Step 5: Solve for x
   x = 8,765.00/80.83
6. Step 6: Final answer
   x = 108.44