Finding the Fourth Proportional to 1,078.82, 1,488.76 and 686.07

Step by Step Solution

1. Step 1: Write the proportion equation
   1,078.82 : 1,488.76 = 686.07 : x
2. Step 2: Convert to fraction form
   1,078.82/1,488.76 = 686.07/x
3. Step 3: Cross multiply
   1,078.82x = 1,488.76 × 686.07
4. Step 4: Simplify right side
   1,078.82x = 1,021,386.13
5. Step 5: Solve for x
   x = 1,021,386.13/1,078.82
6. Step 6: Final answer
   x = 946.77