Finding the Fourth Proportional to 1,223.98, 1,689.33 and 803.59

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.98 : 1,689.33 = 803.59 : x
2. Step 2: Convert to fraction form
   1,223.98/1,689.33 = 803.59/x
3. Step 3: Cross multiply
   1,223.98x = 1,689.33 × 803.59
4. Step 4: Simplify right side
   1,223.98x = 1,357,528.69
5. Step 5: Solve for x
   x = 1,357,528.69/1,223.98
6. Step 6: Final answer
   x = 1,109.11