Finding the Fourth Proportional to 2,142.51, 3,214.23 and 681.78

Step by Step Solution

1. Step 1: Write the proportion equation
   2,142.51 : 3,214.23 = 681.78 : x
2. Step 2: Convert to fraction form
   2,142.51/3,214.23 = 681.78/x
3. Step 3: Cross multiply
   2,142.51x = 3,214.23 × 681.78
4. Step 4: Simplify right side
   2,142.51x = 2,191,397.73
5. Step 5: Solve for x
   x = 2,191,397.73/2,142.51
6. Step 6: Final answer
   x = 1,022.82