Finding the Fourth Proportional to 21,843, 30,142.80 and 12,410.28

Step by Step Solution

1. Step 1: Write the proportion equation
   21,843 : 30,142.80 = 12,410.28 : x
2. Step 2: Convert to fraction form
   21,843/30,142.80 = 12,410.28/x
3. Step 3: Cross multiply
   21,843x = 30,142.80 × 12,410.28
4. Step 4: Simplify right side
   21,843x = 374,080,587.98
5. Step 5: Solve for x
   x = 374,080,587.98/21,843
6. Step 6: Final answer
   x = 17,125.88