Finding the Fourth Proportional to 21,788.70, 30,067.56 and 12,357.60

Step by Step Solution

1. Step 1: Write the proportion equation
   21,788.70 : 30,067.56 = 12,357.60 : x
2. Step 2: Convert to fraction form
   21,788.70/30,067.56 = 12,357.60/x
3. Step 3: Cross multiply
   21,788.70x = 30,067.56 × 12,357.60
4. Step 4: Simplify right side
   21,788.70x = 371,562,879.46
5. Step 5: Solve for x
   x = 371,562,879.46/21,788.70
6. Step 6: Final answer
   x = 17,053.01