Finding the Fourth Proportional to 11,640.65, 17,456.24 and 5,720.09

Step by Step Solution

1. Step 1: Write the proportion equation
   11,640.65 : 17,456.24 = 5,720.09 : x
2. Step 2: Convert to fraction form
   11,640.65/17,456.24 = 5,720.09/x
3. Step 3: Cross multiply
   11,640.65x = 17,456.24 × 5,720.09
4. Step 4: Simplify right side
   11,640.65x = 99,851,190.88
5. Step 5: Solve for x
   x = 99,851,190.88/11,640.65
6. Step 6: Final answer
   x = 8,577.81