Finding the Fourth Proportional to 2,085.12, 3,121.20 and 1,108.80

Step by Step Solution

1. Step 1: Write the proportion equation
   2,085.12 : 3,121.20 = 1,108.80 : x
2. Step 2: Convert to fraction form
   2,085.12/3,121.20 = 1,108.80/x
3. Step 3: Cross multiply
   2,085.12x = 3,121.20 × 1,108.80
4. Step 4: Simplify right side
   2,085.12x = 3,460,786.56
5. Step 5: Solve for x
   x = 3,460,786.56/2,085.12
6. Step 6: Final answer
   x = 1,659.75