Finding the Fourth Proportional to 2,761.78, 3,811.71 and 2,018.20

Step by Step Solution

1. Step 1: Write the proportion equation
   2,761.78 : 3,811.71 = 2,018.20 : x
2. Step 2: Convert to fraction form
   2,761.78/3,811.71 = 2,018.20/x
3. Step 3: Cross multiply
   2,761.78x = 3,811.71 × 2,018.20
4. Step 4: Simplify right side
   2,761.78x = 7,692,793.12
5. Step 5: Solve for x
   x = 7,692,793.12/2,761.78
6. Step 6: Final answer
   x = 2,785.45