Finding the Fourth Proportional to 2,142.80, 3,213.65 and 682.10

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142.80 : 3,213.65 = 682.10 : x
2. Step 2: Convert to fraction form
   2,142.80/3,213.65 = 682.10/x
3. Step 3: Cross multiply
   2,142.80x = 3,213.65 × 682.10
4. Step 4: Simplify right side
   2,142.80x = 2,192,016.30
5. Step 5: Solve for x
   x = 2,192,016.30/2,142.80
6. Step 6: Final answer
   x = 1,022.97