Finding the Fourth Proportional to 1,222.38, 1,686.88 and 698.41

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.38 : 1,686.88 = 698.41 : x
2. Step 2: Convert to fraction form
   1,222.38/1,686.88 = 698.41/x
3. Step 3: Cross multiply
   1,222.38x = 1,686.88 × 698.41
4. Step 4: Simplify right side
   1,222.38x = 1,178,125.43
5. Step 5: Solve for x
   x = 1,178,125.43/1,222.38
6. Step 6: Final answer
   x = 963.80