Finding the Fourth Proportional to 2,057.31, 2,838.41 and 1,218.30

Step by Step Solution

1. Step 1: Write the proportion equation
   2,057.31 : 2,838.41 = 1,218.30 : x
2. Step 2: Convert to fraction form
   2,057.31/2,838.41 = 1,218.30/x
3. Step 3: Cross multiply
   2,057.31x = 2,838.41 × 1,218.30
4. Step 4: Simplify right side
   2,057.31x = 3,458,034.90
5. Step 5: Solve for x
   x = 3,458,034.90/2,057.31
6. Step 6: Final answer
   x = 1,680.85