Finding the Fourth Proportional to 13,853.43, 20,775.42 and 3,990.06

Step by Step Solution

1. Step 1: Write the proportion equation
   13,853.43 : 20,775.42 = 3,990.06 : x
2. Step 2: Convert to fraction form
   13,853.43/20,775.42 = 3,990.06/x
3. Step 3: Cross multiply
   13,853.43x = 20,775.42 × 3,990.06
4. Step 4: Simplify right side
   13,853.43x = 82,895,172.33
5. Step 5: Solve for x
   x = 82,895,172.33/13,853.43
6. Step 6: Final answer
   x = 5,983.73