Finding the Fourth Proportional to 12,728.40, 17,561.16 and 7,422.18

Step by Step Solution

1. Step 1: Write the proportion equation
   12,728.40 : 17,561.16 = 7,422.18 : x
2. Step 2: Convert to fraction form
   12,728.40/17,561.16 = 7,422.18/x
3. Step 3: Cross multiply
   12,728.40x = 17,561.16 × 7,422.18
4. Step 4: Simplify right side
   12,728.40x = 130,342,090.53
5. Step 5: Solve for x
   x = 130,342,090.53/12,728.40
6. Step 6: Final answer
   x = 10,240.26