Finding the Fourth Proportional to 20,472.57, 30,690.59 and 7,989.69

Step by Step Solution

1. Step 1: Write the proportion equation
   20,472.57 : 30,690.59 = 7,989.69 : x
2. Step 2: Convert to fraction form
   20,472.57/30,690.59 = 7,989.69/x
3. Step 3: Cross multiply
   20,472.57x = 30,690.59 × 7,989.69
4. Step 4: Simplify right side
   20,472.57x = 245,208,300.02
5. Step 5: Solve for x
   x = 245,208,300.02/20,472.57
6. Step 6: Final answer
   x = 11,977.41