Finding the Fourth Proportional to 1,079.30, 1,489.59 and 686.90

Step by Step Solution

1. Step 1: Write the proportion equation
   1,079.30 : 1,489.59 = 686.90 : x
2. Step 2: Convert to fraction form
   1,079.30/1,489.59 = 686.90/x
3. Step 3: Cross multiply
   1,079.30x = 1,489.59 × 686.90
4. Step 4: Simplify right side
   1,079.30x = 1,023,199.37
5. Step 5: Solve for x
   x = 1,023,199.37/1,079.30
6. Step 6: Final answer
   x = 948.02