Finding the Fourth Proportional to 21,999, 30,360.24 and 13,617.12

Step by Step Solution

1. Step 1: Write the proportion equation
   21,999 : 30,360.24 = 13,617.12 : x
2. Step 2: Convert to fraction form
   21,999/30,360.24 = 13,617.12/x
3. Step 3: Cross multiply
   21,999x = 30,360.24 × 13,617.12
4. Step 4: Simplify right side
   21,999x = 413,419,031.31
5. Step 5: Solve for x
   x = 413,419,031.31/21,999
6. Step 6: Final answer
   x = 18,792.63