Finding the Fourth Proportional to 21,938.43, 30,266.42 and 12,982.67

Step by Step Solution

1. Step 1: Write the proportion equation
   21,938.43 : 30,266.42 = 12,982.67 : x
2. Step 2: Convert to fraction form
   21,938.43/30,266.42 = 12,982.67/x
3. Step 3: Cross multiply
   21,938.43x = 30,266.42 × 12,982.67
4. Step 4: Simplify right side
   21,938.43x = 392,938,942.94
5. Step 5: Solve for x
   x = 392,938,942.94/21,938.43
6. Step 6: Final answer
   x = 17,910.99