Finding the Fourth Proportional to 3,456.42, 5,183.82 and 990.78

Step by Step Solution

1. Step 1: Write the proportion equation
   3,456.42 : 5,183.82 = 990.78 : x
2. Step 2: Convert to fraction form
   3,456.42/5,183.82 = 990.78/x
3. Step 3: Cross multiply
   3,456.42x = 5,183.82 × 990.78
4. Step 4: Simplify right side
   3,456.42x = 5,136,025.18
5. Step 5: Solve for x
   x = 5,136,025.18/3,456.42
6. Step 6: Final answer
   x = 1,485.94