Finding the Fourth Proportional to 2,857.06, 3,944.59 and 2,557.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,857.06 : 3,944.59 = 2,557.78 : x
2. Step 2: Convert to fraction form
   2,857.06/3,944.59 = 2,557.78/x
3. Step 3: Cross multiply
   2,857.06x = 3,944.59 × 2,557.78
4. Step 4: Simplify right side
   2,857.06x = 10,089,393.41
5. Step 5: Solve for x
   x = 10,089,393.41/2,857.06
6. Step 6: Final answer
   x = 3,531.39