Finding the Fourth Proportional to 21,858, 30,153.24 and 13,788

Step by Step Solution

1. Step 1: Write the proportion equation
   21,858 : 30,153.24 = 13,788 : x
2. Step 2: Convert to fraction form
   21,858/30,153.24 = 13,788/x
3. Step 3: Cross multiply
   21,858x = 30,153.24 × 13,788
4. Step 4: Simplify right side
   21,858x = 415,752,873.12
5. Step 5: Solve for x
   x = 415,752,873.12/21,858
6. Step 6: Final answer
   x = 19,020.63