Finding the Fourth Proportional to 12,399.50, 17,110.69 and 7,021.10

Step by Step Solution

1. Step 1: Write the proportion equation
   12,399.50 : 17,110.69 = 7,021.10 : x
2. Step 2: Convert to fraction form
   12,399.50/17,110.69 = 7,021.10/x
3. Step 3: Cross multiply
   12,399.50x = 17,110.69 × 7,021.10
4. Step 4: Simplify right side
   12,399.50x = 120,135,762.45
5. Step 5: Solve for x
   x = 120,135,762.45/12,399.50
6. Step 6: Final answer
   x = 9,688.76