Finding the Fourth Proportional to 1,222.11, 1,686.56 and 698.31

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.11 : 1,686.56 = 698.31 : x
2. Step 2: Convert to fraction form
   1,222.11/1,686.56 = 698.31/x
3. Step 3: Cross multiply
   1,222.11x = 1,686.56 × 698.31
4. Step 4: Simplify right side
   1,222.11x = 1,177,738.22
5. Step 5: Solve for x
   x = 1,177,738.22/1,222.11
6. Step 6: Final answer
   x = 963.69