Finding the Fourth Proportional to 1,781.59, 2,672.78 and 686.47

Step by Step Solution

1. Step 1: Write the proportion equation
   1,781.59 : 2,672.78 = 686.47 : x
2. Step 2: Convert to fraction form
   1,781.59/2,672.78 = 686.47/x
3. Step 3: Cross multiply
   1,781.59x = 2,672.78 × 686.47
4. Step 4: Simplify right side
   1,781.59x = 1,834,783.29
5. Step 5: Solve for x
   x = 1,834,783.29/1,781.59
6. Step 6: Final answer
   x = 1,029.86