Finding the Fourth Proportional to 1,222.76, 1,687.24 and 691.56

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.76 : 1,687.24 = 691.56 : x
2. Step 2: Convert to fraction form
   1,222.76/1,687.24 = 691.56/x
3. Step 3: Cross multiply
   1,222.76x = 1,687.24 × 691.56
4. Step 4: Simplify right side
   1,222.76x = 1,166,827.69
5. Step 5: Solve for x
   x = 1,166,827.69/1,222.76
6. Step 6: Final answer
   x = 954.26