Finding the Fourth Proportional to 21,828.05, 30,121.56 and 12,396

Step by Step Solution

1. Step 1: Write the proportion equation
   21,828.05 : 30,121.56 = 12,396 : x
2. Step 2: Convert to fraction form
   21,828.05/30,121.56 = 12,396/x
3. Step 3: Cross multiply
   21,828.05x = 30,121.56 × 12,396
4. Step 4: Simplify right side
   21,828.05x = 373,386,857.76
5. Step 5: Solve for x
   x = 373,386,857.76/21,828.05
6. Step 6: Final answer
   x = 17,105.83