Finding the Fourth Proportional to 1,222.61, 1,686.76 and 698.33

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.61 : 1,686.76 = 698.33 : x
2. Step 2: Convert to fraction form
   1,222.61/1,686.76 = 698.33/x
3. Step 3: Cross multiply
   1,222.61x = 1,686.76 × 698.33
4. Step 4: Simplify right side
   1,222.61x = 1,177,917.58
5. Step 5: Solve for x
   x = 1,177,917.58/1,222.61
6. Step 6: Final answer
   x = 963.45