Finding the Fourth Proportional to 21,899.61, 30,219.71 and 12,339.09

Step by Step Solution

1. Step 1: Write the proportion equation
   21,899.61 : 30,219.71 = 12,339.09 : x
2. Step 2: Convert to fraction form
   21,899.61/30,219.71 = 12,339.09/x
3. Step 3: Cross multiply
   21,899.61x = 30,219.71 × 12,339.09
4. Step 4: Simplify right side
   21,899.61x = 372,883,659.77
5. Step 5: Solve for x
   x = 372,883,659.77/21,899.61
6. Step 6: Final answer
   x = 17,026.95