Finding the Fourth Proportional to 20,401.99, 30,599.46 and 5,409.21

Step by Step Solution

1. Step 1: Write the proportion equation
   20,401.99 : 30,599.46 = 5,409.21 : x
2. Step 2: Convert to fraction form
   20,401.99/30,599.46 = 5,409.21/x
3. Step 3: Cross multiply
   20,401.99x = 30,599.46 × 5,409.21
4. Step 4: Simplify right side
   20,401.99x = 165,518,905.03
5. Step 5: Solve for x
   x = 165,518,905.03/20,401.99
6. Step 6: Final answer
   x = 8,112.88