Finding the Fourth Proportional to 21,912, 30,238.56 and 12,486.03

Step by Step Solution

1. Step 1: Write the proportion equation
   21,912 : 30,238.56 = 12,486.03 : x
2. Step 2: Convert to fraction form
   21,912/30,238.56 = 12,486.03/x
3. Step 3: Cross multiply
   21,912x = 30,238.56 × 12,486.03
4. Step 4: Simplify right side
   21,912x = 377,559,567.32
5. Step 5: Solve for x
   x = 377,559,567.32/21,912
6. Step 6: Final answer
   x = 17,230.72