Finding the Fourth Proportional to 11,721.50, 17,581.33 and 5,147.74

Step by Step Solution

1. Step 1: Write the proportion equation
   11,721.50 : 17,581.33 = 5,147.74 : x
2. Step 2: Convert to fraction form
   11,721.50/17,581.33 = 5,147.74/x
3. Step 3: Cross multiply
   11,721.50x = 17,581.33 × 5,147.74
4. Step 4: Simplify right side
   11,721.50x = 90,504,115.69
5. Step 5: Solve for x
   x = 90,504,115.69/11,721.50
6. Step 6: Final answer
   x = 7,721.21