Finding the Fourth Proportional to 21,411.52, 29,548.72 and 11,979.88

Step by Step Solution

1. Step 1: Write the proportion equation
   21,411.52 : 29,548.72 = 11,979.88 : x
2. Step 2: Convert to fraction form
   21,411.52/29,548.72 = 11,979.88/x
3. Step 3: Cross multiply
   21,411.52x = 29,548.72 × 11,979.88
4. Step 4: Simplify right side
   21,411.52x = 353,990,119.75
5. Step 5: Solve for x
   x = 353,990,119.75/21,411.52
6. Step 6: Final answer
   x = 16,532.69