Finding the Fourth Proportional to 21,818.47, 30,109.89 and 12,128.84

Step by Step Solution

1. Step 1: Write the proportion equation
   21,818.47 : 30,109.89 = 12,128.84 : x
2. Step 2: Convert to fraction form
   21,818.47/30,109.89 = 12,128.84/x
3. Step 3: Cross multiply
   21,818.47x = 30,109.89 × 12,128.84
4. Step 4: Simplify right side
   21,818.47x = 365,197,962.95
5. Step 5: Solve for x
   x = 365,197,962.95/21,818.47
6. Step 6: Final answer
   x = 16,738.02