Finding the Fourth Proportional to 3,998.76, 5,982.12 and 3,456.78

Step by Step Solution

1. Step 1: Write the proportion equation
   3,998.76 : 5,982.12 = 3,456.78 : x
2. Step 2: Convert to fraction form
   3,998.76/5,982.12 = 3,456.78/x
3. Step 3: Cross multiply
   3,998.76x = 5,982.12 × 3,456.78
4. Step 4: Simplify right side
   3,998.76x = 20,678,900.69
5. Step 5: Solve for x
   x = 20,678,900.69/3,998.76
6. Step 6: Final answer
   x = 5,171.33