Finding the Fourth Proportional to 21,885, 30,190.50 and 13,815.06

Step by Step Solution

1. Step 1: Write the proportion equation
   21,885 : 30,190.50 = 13,815.06 : x
2. Step 2: Convert to fraction form
   21,885/30,190.50 = 13,815.06/x
3. Step 3: Cross multiply
   21,885x = 30,190.50 × 13,815.06
4. Step 4: Simplify right side
   21,885x = 417,083,568.93
5. Step 5: Solve for x
   x = 417,083,568.93/21,885
6. Step 6: Final answer
   x = 19,057.97