Finding the Fourth Proportional to 2,057.64, 2,839.88 and 1,218.56

Step by Step Solution

1. Step 1: Write the proportion equation
   2,057.64 : 2,839.88 = 1,218.56 : x
2. Step 2: Convert to fraction form
   2,057.64/2,839.88 = 1,218.56/x
3. Step 3: Cross multiply
   2,057.64x = 2,839.88 × 1,218.56
4. Step 4: Simplify right side
   2,057.64x = 3,460,564.17
5. Step 5: Solve for x
   x = 3,460,564.17/2,057.64
6. Step 6: Final answer
   x = 1,681.81