Finding the Fourth Proportional to 13,709, 18,918.42 and 7,421.42

Step by Step Solution

1. Step 1: Write the proportion equation
   13,709 : 18,918.42 = 7,421.42 : x
2. Step 2: Convert to fraction form
   13,709/18,918.42 = 7,421.42/x
3. Step 3: Cross multiply
   13,709x = 18,918.42 × 7,421.42
4. Step 4: Simplify right side
   13,709x = 140,401,540.56
5. Step 5: Solve for x
   x = 140,401,540.56/13,709
6. Step 6: Final answer
   x = 10,241.56