Finding the Fourth Proportional to 21,218.43, 29,286.71 and 12,271.13

Step by Step Solution

1. Step 1: Write the proportion equation
   21,218.43 : 29,286.71 = 12,271.13 : x
2. Step 2: Convert to fraction form
   21,218.43/29,286.71 = 12,271.13/x
3. Step 3: Cross multiply
   21,218.43x = 29,286.71 × 12,271.13
4. Step 4: Simplify right side
   21,218.43x = 359,380,817.89
5. Step 5: Solve for x
   x = 359,380,817.89/21,218.43
6. Step 6: Final answer
   x = 16,937.20