Finding the Fourth Proportional to 12,426.12, 17,147.55 and 7,117.20

Step by Step Solution

1. Step 1: Write the proportion equation
   12,426.12 : 17,147.55 = 7,117.20 : x
2. Step 2: Convert to fraction form
   12,426.12/17,147.55 = 7,117.20/x
3. Step 3: Cross multiply
   12,426.12x = 17,147.55 × 7,117.20
4. Step 4: Simplify right side
   12,426.12x = 122,042,542.86
5. Step 5: Solve for x
   x = 122,042,542.86/12,426.12
6. Step 6: Final answer
   x = 9,821.45