Finding the Fourth Proportional to 21,015.47, 28,992.15 and 13,836.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,015.47 : 28,992.15 = 13,836.12 : x
2. Step 2: Convert to fraction form
   21,015.47/28,992.15 = 13,836.12/x
3. Step 3: Cross multiply
   21,015.47x = 28,992.15 × 13,836.12
4. Step 4: Simplify right side
   21,015.47x = 401,138,866.46
5. Step 5: Solve for x
   x = 401,138,866.46/21,015.47
6. Step 6: Final answer
   x = 19,087.79