Finding the Fourth Proportional to 1,222.63, 1,687.29 and 698.83

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.63 : 1,687.29 = 698.83 : x
2. Step 2: Convert to fraction form
   1,222.63/1,687.29 = 698.83/x
3. Step 3: Cross multiply
   1,222.63x = 1,687.29 × 698.83
4. Step 4: Simplify right side
   1,222.63x = 1,179,128.87
5. Step 5: Solve for x
   x = 1,179,128.87/1,222.63
6. Step 6: Final answer
   x = 964.42