Finding the Fourth Proportional to 80.60, 120.78 and 42.08

Step by Step Solution

1. Step 1: Write the proportion equation
   80.60 : 120.78 = 42.08 : x
2. Step 2: Convert to fraction form
   80.60/120.78 = 42.08/x
3. Step 3: Cross multiply
   80.60x = 120.78 × 42.08
4. Step 4: Simplify right side
   80.60x = 5,081.82
5. Step 5: Solve for x
   x = 5,081.82/80.60
6. Step 6: Final answer
   x = 63.05