Finding the Fourth Proportional to 21,916.82, 30,237.82 and 12,478.70

Step by Step Solution

1. Step 1: Write the proportion equation
   21,916.82 : 30,237.82 = 12,478.70 : x
2. Step 2: Convert to fraction form
   21,916.82/30,237.82 = 12,478.70/x
3. Step 3: Cross multiply
   21,916.82x = 30,237.82 × 12,478.70
4. Step 4: Simplify right side
   21,916.82x = 377,328,470.85
5. Step 5: Solve for x
   x = 377,328,470.85/21,916.82
6. Step 6: Final answer
   x = 17,216.39