Finding the Fourth Proportional to 1,223.39, 1,687.82 and 803.98

Step by Step Solution

1. Step 1: Write the proportion equation
   1,223.39 : 1,687.82 = 803.98 : x
2. Step 2: Convert to fraction form
   1,223.39/1,687.82 = 803.98/x
3. Step 3: Cross multiply
   1,223.39x = 1,687.82 × 803.98
4. Step 4: Simplify right side
   1,223.39x = 1,356,965.28
5. Step 5: Solve for x
   x = 1,356,965.28/1,223.39
6. Step 6: Final answer
   x = 1,109.18