Finding the Fourth Proportional to 21,909.94, 30,235.72 and 12,479.38

Step by Step Solution

1. Step 1: Write the proportion equation
   21,909.94 : 30,235.72 = 12,479.38 : x
2. Step 2: Convert to fraction form
   21,909.94/30,235.72 = 12,479.38/x
3. Step 3: Cross multiply
   21,909.94x = 30,235.72 × 12,479.38
4. Step 4: Simplify right side
   21,909.94x = 377,322,932.67
5. Step 5: Solve for x
   x = 377,322,932.67/21,909.94
6. Step 6: Final answer
   x = 17,221.54