Finding the Fourth Proportional to 21,890.76, 30,209.39 and 12,459.32

Step by Step Solution

1. Step 1: Write the proportion equation
   21,890.76 : 30,209.39 = 12,459.32 : x
2. Step 2: Convert to fraction form
   21,890.76/30,209.39 = 12,459.32/x
3. Step 3: Cross multiply
   21,890.76x = 30,209.39 × 12,459.32
4. Step 4: Simplify right side
   21,890.76x = 376,388,243.67
5. Step 5: Solve for x
   x = 376,388,243.67/21,890.76
6. Step 6: Final answer
   x = 17,193.93