Finding the Fourth Proportional to 21,411.05, 29,547.32 and 11,979

Step by Step Solution

1. Step 1: Write the proportion equation
   21,411.05 : 29,547.32 = 11,979 : x
2. Step 2: Convert to fraction form
   21,411.05/29,547.32 = 11,979/x
3. Step 3: Cross multiply
   21,411.05x = 29,547.32 × 11,979
4. Step 4: Simplify right side
   21,411.05x = 353,947,286.39
5. Step 5: Solve for x
   x = 353,947,286.39/21,411.05
6. Step 6: Final answer
   x = 16,531.06