Finding the Fourth Proportional to 21,877.40, 30,187.55 and 12,315.89

Step by Step Solution

1. Step 1: Write the proportion equation
   21,877.40 : 30,187.55 = 12,315.89 : x
2. Step 2: Convert to fraction form
   21,877.40/30,187.55 = 12,315.89/x
3. Step 3: Cross multiply
   21,877.40x = 30,187.55 × 12,315.89
4. Step 4: Simplify right side
   21,877.40x = 371,786,425.02
5. Step 5: Solve for x
   x = 371,786,425.02/21,877.40
6. Step 6: Final answer
   x = 16,994.09