Finding the Fourth Proportional to 21,820.50, 30,109.79 and 12,259.11

Step by Step Solution

1. Step 1: Write the proportion equation
   21,820.50 : 30,109.79 = 12,259.11 : x
2. Step 2: Convert to fraction form
   21,820.50/30,109.79 = 12,259.11/x
3. Step 3: Cross multiply
   21,820.50x = 30,109.79 × 12,259.11
4. Step 4: Simplify right side
   21,820.50x = 369,119,227.69
5. Step 5: Solve for x
   x = 369,119,227.69/21,820.50
6. Step 6: Final answer
   x = 16,916.17