Finding the Fourth Proportional to 1,222.17, 1,686.46 and 698.10

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.17 : 1,686.46 = 698.10 : x
2. Step 2: Convert to fraction form
   1,222.17/1,686.46 = 698.10/x
3. Step 3: Cross multiply
   1,222.17x = 1,686.46 × 698.10
4. Step 4: Simplify right side
   1,222.17x = 1,177,314.24
5. Step 5: Solve for x
   x = 1,177,314.24/1,222.17
6. Step 6: Final answer
   x = 963.30