Finding the Fourth Proportional to 1,222.52, 1,687.25 and 691.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.52 : 1,687.25 = 691.56 : x
2. Step 2: Convert to fraction form
   1,222.52/1,687.25 = 691.56/x
3. Step 3: Cross multiply
   1,222.52x = 1,687.25 × 691.56
4. Step 4: Simplify right side
   1,222.52x = 1,166,831.15
5. Step 5: Solve for x
   x = 1,166,831.15/1,222.52
6. Step 6: Final answer
   x = 954.45