Finding the Fourth Proportional to 1,222.88, 1,687.76 and 698.96

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.88 : 1,687.76 = 698.96 : x
2. Step 2: Convert to fraction form
   1,222.88/1,687.76 = 698.96/x
3. Step 3: Cross multiply
   1,222.88x = 1,687.76 × 698.96
4. Step 4: Simplify right side
   1,222.88x = 1,179,676.73
5. Step 5: Solve for x
   x = 1,179,676.73/1,222.88
6. Step 6: Final answer
   x = 964.67