Finding the Fourth Proportional to 20,621, 30,947.89 and 7,477.12

Step by Step Solution

1. Step 1: Write the proportion equation
   20,621 : 30,947.89 = 7,477.12 : x
2. Step 2: Convert to fraction form
   20,621/30,947.89 = 7,477.12/x
3. Step 3: Cross multiply
   20,621x = 30,947.89 × 7,477.12
4. Step 4: Simplify right side
   20,621x = 231,401,087.28
5. Step 5: Solve for x
   x = 231,401,087.28/20,621
6. Step 6: Final answer
   x = 11,221.62