Finding the Fourth Proportional to 19,721.20, 29,556.12 and 8,020.72

Step by Step Solution

1. Step 1: Write the proportion equation
   19,721.20 : 29,556.12 = 8,020.72 : x
2. Step 2: Convert to fraction form
   19,721.20/29,556.12 = 8,020.72/x
3. Step 3: Cross multiply
   19,721.20x = 29,556.12 × 8,020.72
4. Step 4: Simplify right side
   19,721.20x = 237,061,362.81
5. Step 5: Solve for x
   x = 237,061,362.81/19,721.20
6. Step 6: Final answer
   x = 12,020.64