Finding the Fourth Proportional to 21,578.53, 29,778.42 and 12,018.34

Step by Step Solution

1. Step 1: Write the proportion equation
   21,578.53 : 29,778.42 = 12,018.34 : x
2. Step 2: Convert to fraction form
   21,578.53/29,778.42 = 12,018.34/x
3. Step 3: Cross multiply
   21,578.53x = 29,778.42 × 12,018.34
4. Step 4: Simplify right side
   21,578.53x = 357,887,176.22
5. Step 5: Solve for x
   x = 357,887,176.22/21,578.53
6. Step 6: Final answer
   x = 16,585.34