Finding the Fourth Proportional to 112.45, 168.69 and 80.10

Step by Step Solution

1. Step 1: Write the proportion equation
   112.45 : 168.69 = 80.10 : x
2. Step 2: Convert to fraction form
   112.45/168.69 = 80.10/x
3. Step 3: Cross multiply
   112.45x = 168.69 × 80.10
4. Step 4: Simplify right side
   112.45x = 13,510.83
5. Step 5: Solve for x
   x = 13,510.83/112.45
6. Step 6: Final answer
   x = 120.15