Finding the Fourth Proportional to 2,555.36, 3,831.12 and 1,321.12

Step by Step Solution

1. Step 1: Write the proportion equation
   2,555.36 : 3,831.12 = 1,321.12 : x
2. Step 2: Convert to fraction form
   2,555.36/3,831.12 = 1,321.12/x
3. Step 3: Cross multiply
   2,555.36x = 3,831.12 × 1,321.12
4. Step 4: Simplify right side
   2,555.36x = 5,061,369.25
5. Step 5: Solve for x
   x = 5,061,369.25/2,555.36
6. Step 6: Final answer
   x = 1,980.69