Finding the Fourth Proportional to 21,978, 30,329.68 and 12,042

Step by Step Solution

1. Step 1: Write the proportion equation
   21,978 : 30,329.68 = 12,042 : x
2. Step 2: Convert to fraction form
   21,978/30,329.68 = 12,042/x
3. Step 3: Cross multiply
   21,978x = 30,329.68 × 12,042
4. Step 4: Simplify right side
   21,978x = 365,230,006.56
5. Step 5: Solve for x
   x = 365,230,006.56/21,978
6. Step 6: Final answer
   x = 16,617.98