Finding the Fourth Proportional to 1,222.69, 1,687.29 and 698.68

Step by Step Solution

1. Step 1: Write the proportion equation
   1,222.69 : 1,687.29 = 698.68 : x
2. Step 2: Convert to fraction form
   1,222.69/1,687.29 = 698.68/x
3. Step 3: Cross multiply
   1,222.69x = 1,687.29 × 698.68
4. Step 4: Simplify right side
   1,222.69x = 1,178,875.78
5. Step 5: Solve for x
   x = 1,178,875.78/1,222.69
6. Step 6: Final answer
   x = 964.17