Finding the Fourth Proportional to 21,579.63, 29,779.42 and 12,019.48

Step by Step Solution

1. Step 1: Write the proportion equation
   21,579.63 : 29,779.42 = 12,019.48 : x
2. Step 2: Convert to fraction form
   21,579.63/29,779.42 = 12,019.48/x
3. Step 3: Cross multiply
   21,579.63x = 29,779.42 × 12,019.48
4. Step 4: Simplify right side
   21,579.63x = 357,933,143.10
5. Step 5: Solve for x
   x = 357,933,143.10/21,579.63
6. Step 6: Final answer
   x = 16,586.62