Finding the Fourth Proportional to 12,422.78, 17,145.88 and 7,121.16

Step by Step Solution

1. Step 1: Write the proportion equation
   12,422.78 : 17,145.88 = 7,121.16 : x
2. Step 2: Convert to fraction form
   12,422.78/17,145.88 = 7,121.16/x
3. Step 3: Cross multiply
   12,422.78x = 17,145.88 × 7,121.16
4. Step 4: Simplify right side
   12,422.78x = 122,098,554.82
5. Step 5: Solve for x
   x = 122,098,554.82/12,422.78
6. Step 6: Final answer
   x = 9,828.60