Finding the Fourth Proportional to 1,222.71, 1,687.41 and 698.82

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.71 : 1,687.41 = 698.82 : x
2. Step 2: Convert to fraction form
   1,222.71/1,687.41 = 698.82/x
3. Step 3: Cross multiply
   1,222.71x = 1,687.41 × 698.82
4. Step 4: Simplify right side
   1,222.71x = 1,179,195.86
5. Step 5: Solve for x
   x = 1,179,195.86/1,222.71
6. Step 6: Final answer
   x = 964.41