Finding the Fourth Proportional to 8,490.29, 12,721.61 and 5,196.47

Step by Step Solution

1. Step 1: Write the proportion equation
   8,490.29 : 12,721.61 = 5,196.47 : x
2. Step 2: Convert to fraction form
   8,490.29/12,721.61 = 5,196.47/x
3. Step 3: Cross multiply
   8,490.29x = 12,721.61 × 5,196.47
4. Step 4: Simplify right side
   8,490.29x = 66,107,438.73
5. Step 5: Solve for x
   x = 66,107,438.73/8,490.29
6. Step 6: Final answer
   x = 7,786.24