Finding the Fourth Proportional to 1,248.79, 1,723.31 and 689.23

Step by Step Solution

1. Step 1: Write the proportion equation
   1,248.79 : 1,723.31 = 689.23 : x
2. Step 2: Convert to fraction form
   1,248.79/1,723.31 = 689.23/x
3. Step 3: Cross multiply
   1,248.79x = 1,723.31 × 689.23
4. Step 4: Simplify right side
   1,248.79x = 1,187,744.89
5. Step 5: Solve for x
   x = 1,187,744.89/1,248.79
6. Step 6: Final answer
   x = 951.12