Finding the Fourth Proportional to 11,921.31, 16,451.69 and 6,616.42

Step by Step Solution

1. Step 1: Write the proportion equation
   11,921.31 : 16,451.69 = 6,616.42 : x
2. Step 2: Convert to fraction form
   11,921.31/16,451.69 = 6,616.42/x
3. Step 3: Cross multiply
   11,921.31x = 16,451.69 × 6,616.42
4. Step 4: Simplify right side
   11,921.31x = 108,851,216.54
5. Step 5: Solve for x
   x = 108,851,216.54/11,921.31
6. Step 6: Final answer
   x = 9,130.81