Finding the Fourth Proportional to 3,456.16, 5,182.72 and 990.42

Step by Step Solution

1. Step 1: Write the proportion equation
   3,456.16 : 5,182.72 = 990.42 : x
2. Step 2: Convert to fraction form
   3,456.16/5,182.72 = 990.42/x
3. Step 3: Cross multiply
   3,456.16x = 5,182.72 × 990.42
4. Step 4: Simplify right side
   3,456.16x = 5,133,064.59
5. Step 5: Solve for x
   x = 5,133,064.59/3,456.16
6. Step 6: Final answer
   x = 1,485.19