Finding the Fourth Proportional to 21,819.87, 30,112.35 and 12,389.31

Step by Step Solution

1. Step 1: Write the proportion equation
   21,819.87 : 30,112.35 = 12,389.31 : x
2. Step 2: Convert to fraction form
   21,819.87/30,112.35 = 12,389.31/x
3. Step 3: Cross multiply
   21,819.87x = 30,112.35 × 12,389.31
4. Step 4: Simplify right side
   21,819.87x = 373,071,026.47
5. Step 5: Solve for x
   x = 373,071,026.47/21,819.87
6. Step 6: Final answer
   x = 17,097.77