Finding the Fourth Proportional to 21,009.27, 31,513.79 and 12,118.84

Step by Step Solution

1. Step 1: Write the proportion equation
   21,009.27 : 31,513.79 = 12,118.84 : x
2. Step 2: Convert to fraction form
   21,009.27/31,513.79 = 12,118.84/x
3. Step 3: Cross multiply
   21,009.27x = 31,513.79 × 12,118.84
4. Step 4: Simplify right side
   21,009.27x = 381,910,578.80
5. Step 5: Solve for x
   x = 381,910,578.80/21,009.27
6. Step 6: Final answer
   x = 18,178.19