Finding the Fourth Proportional to 21,984.89, 30,339.18 and 12,908.49

Step by Step Solution

1. Step 1: Write the proportion equation
   21,984.89 : 30,339.18 = 12,908.49 : x
2. Step 2: Convert to fraction form
   21,984.89/30,339.18 = 12,908.49/x
3. Step 3: Cross multiply
   21,984.89x = 30,339.18 × 12,908.49
4. Step 4: Simplify right side
   21,984.89x = 391,633,001.64
5. Step 5: Solve for x
   x = 391,633,001.64/21,984.89
6. Step 6: Final answer
   x = 17,813.74