Finding the Fourth Proportional to 21,890.48, 30,210.16 and 12,459.10

Step by Step Solution

1. Step 1: Write the proportion equation
   21,890.48 : 30,210.16 = 12,459.10 : x
2. Step 2: Convert to fraction form
   21,890.48/30,210.16 = 12,459.10/x
3. Step 3: Cross multiply
   21,890.48x = 30,210.16 × 12,459.10
4. Step 4: Simplify right side
   21,890.48x = 376,391,404.46
5. Step 5: Solve for x
   x = 376,391,404.46/21,890.48
6. Step 6: Final answer
   x = 17,194.30