Finding the Fourth Proportional to 1,028.72, 1,543.16 and 686

Step by Step Solution

1. Step 1: Write the proportion equation
   1,028.72 : 1,543.16 = 686 : x
2. Step 2: Convert to fraction form
   1,028.72/1,543.16 = 686/x
3. Step 3: Cross multiply
   1,028.72x = 1,543.16 × 686
4. Step 4: Simplify right side
   1,028.72x = 1,058,607.76
5. Step 5: Solve for x
   x = 1,058,607.76/1,028.72
6. Step 6: Final answer
   x = 1,029.05