Finding the Fourth Proportional to 21,989.46, 30,342.96 and 12,428.22

Step by Step Solution

1. Step 1: Write the proportion equation
   21,989.46 : 30,342.96 = 12,428.22 : x
2. Step 2: Convert to fraction form
   21,989.46/30,342.96 = 12,428.22/x
3. Step 3: Cross multiply
   21,989.46x = 30,342.96 × 12,428.22
4. Step 4: Simplify right side
   21,989.46x = 377,108,982.33
5. Step 5: Solve for x
   x = 377,108,982.33/21,989.46
6. Step 6: Final answer
   x = 17,149.53