Finding the Fourth Proportional to 2,015.72, 2,781.60 and 1,131.48

Step by Step Solution

1. Step 1: Write the proportion equation
   2,015.72 : 2,781.60 = 1,131.48 : x
2. Step 2: Convert to fraction form
   2,015.72/2,781.60 = 1,131.48/x
3. Step 3: Cross multiply
   2,015.72x = 2,781.60 × 1,131.48
4. Step 4: Simplify right side
   2,015.72x = 3,147,324.77
5. Step 5: Solve for x
   x = 3,147,324.77/2,015.72
6. Step 6: Final answer
   x = 1,561.39