Finding the Fourth Proportional to 3,456.42, 5,183.87 and 990.69

Step by Step Solution

1. Step 1: Write the proportion equation
   3,456.42 : 5,183.87 = 990.69 : x
2. Step 2: Convert to fraction form
   3,456.42/5,183.87 = 990.69/x
3. Step 3: Cross multiply
   3,456.42x = 5,183.87 × 990.69
4. Step 4: Simplify right side
   3,456.42x = 5,135,603.22
5. Step 5: Solve for x
   x = 5,135,603.22/3,456.42
6. Step 6: Final answer
   x = 1,485.82