Finding the Fourth Proportional to 21,834.69, 30,130.56 and 12,885

Step by Step Solution

1. Step 1: Write the proportion equation
   21,834.69 : 30,130.56 = 12,885 : x
2. Step 2: Convert to fraction form
   21,834.69/30,130.56 = 12,885/x
3. Step 3: Cross multiply
   21,834.69x = 30,130.56 × 12,885
4. Step 4: Simplify right side
   21,834.69x = 388,232,265.60
5. Step 5: Solve for x
   x = 388,232,265.60/21,834.69
6. Step 6: Final answer
   x = 17,780.53