Finding the Fourth Proportional to 1,248.27, 1,722.71 and 688.79

Step by Step Solution

1. Step 1: Write the proportion equation
   1,248.27 : 1,722.71 = 688.79 : x
2. Step 2: Convert to fraction form
   1,248.27/1,722.71 = 688.79/x
3. Step 3: Cross multiply
   1,248.27x = 1,722.71 × 688.79
4. Step 4: Simplify right side
   1,248.27x = 1,186,585.42
5. Step 5: Solve for x
   x = 1,186,585.42/1,248.27
6. Step 6: Final answer
   x = 950.58