Finding the Fourth Proportional to 1,223.01, 1,687.34 and 691.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.01 : 1,687.34 = 691.83 : x
2. Step 2: Convert to fraction form
   1,223.01/1,687.34 = 691.83/x
3. Step 3: Cross multiply
   1,223.01x = 1,687.34 × 691.83
4. Step 4: Simplify right side
   1,223.01x = 1,167,340.54
5. Step 5: Solve for x
   x = 1,167,340.54/1,223.01
6. Step 6: Final answer
   x = 954.49