Finding the Fourth Proportional to 2,015.91, 2,781.81 and 1,131.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,015.91 : 2,781.81 = 1,131.55 : x
2. Step 2: Convert to fraction form
   2,015.91/2,781.81 = 1,131.55/x
3. Step 3: Cross multiply
   2,015.91x = 2,781.81 × 1,131.55
4. Step 4: Simplify right side
   2,015.91x = 3,147,750.15
5. Step 5: Solve for x
   x = 3,147,750.15/2,015.91
6. Step 6: Final answer
   x = 1,561.45