Finding the Fourth Proportional to 21,978.54, 30,328.56 and 12,419.26

Step by Step Solution

1. Step 1: Write the proportion equation
   21,978.54 : 30,328.56 = 12,419.26 : x
2. Step 2: Convert to fraction form
   21,978.54/30,328.56 = 12,419.26/x
3. Step 3: Cross multiply
   21,978.54x = 30,328.56 × 12,419.26
4. Step 4: Simplify right side
   21,978.54x = 376,658,196.24
5. Step 5: Solve for x
   x = 376,658,196.24/21,978.54
6. Step 6: Final answer
   x = 17,137.54