Finding the Fourth Proportional to 2,015.20, 2,781.09 and 1,131.28

Step by Step Solution

1. Step 1: Write the proportion equation
   2,015.20 : 2,781.09 = 1,131.28 : x
2. Step 2: Convert to fraction form
   2,015.20/2,781.09 = 1,131.28/x
3. Step 3: Cross multiply
   2,015.20x = 2,781.09 × 1,131.28
4. Step 4: Simplify right side
   2,015.20x = 3,146,191.50
5. Step 5: Solve for x
   x = 3,146,191.50/2,015.20
6. Step 6: Final answer
   x = 1,561.23