Finding the Fourth Proportional to 2,015.77, 2,781.78 and 1,131.55

Step by Step Solution

1. Step 1: Write the proportion equation
   2,015.77 : 2,781.78 = 1,131.55 : x
2. Step 2: Convert to fraction form
   2,015.77/2,781.78 = 1,131.55/x
3. Step 3: Cross multiply
   2,015.77x = 2,781.78 × 1,131.55
4. Step 4: Simplify right side
   2,015.77x = 3,147,723.16
5. Step 5: Solve for x
   x = 3,147,723.16/2,015.77
6. Step 6: Final answer
   x = 1,561.55