Finding the Fourth Proportional to 1,079.16, 1,489.41 and 686.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,079.16 : 1,489.41 = 686.31 : x
2. Step 2: Convert to fraction form
   1,079.16/1,489.41 = 686.31/x
3. Step 3: Cross multiply
   1,079.16x = 1,489.41 × 686.31
4. Step 4: Simplify right side
   1,079.16x = 1,022,196.98
5. Step 5: Solve for x
   x = 1,022,196.98/1,079.16
6. Step 6: Final answer
   x = 947.22