Finding the Fourth Proportional to 20,470.57, 30,687.59 and 7,987.69

Step by Step Solution

1. Step 1: Write the proportion equation
   20,470.57 : 30,687.59 = 7,987.69 : x
2. Step 2: Convert to fraction form
   20,470.57/30,687.59 = 7,987.69/x
3. Step 3: Cross multiply
   20,470.57x = 30,687.59 × 7,987.69
4. Step 4: Simplify right side
   20,470.57x = 245,123,039.63
5. Step 5: Solve for x
   x = 245,123,039.63/20,470.57
6. Step 6: Final answer
   x = 11,974.41