Finding the Fourth Proportional to 13,422.88, 18,513.31 and 9,119.30

Step by Step Solution

1. Step 1: Write the proportion equation
   13,422.88 : 18,513.31 = 9,119.30 : x
2. Step 2: Convert to fraction form
   13,422.88/18,513.31 = 9,119.30/x
3. Step 3: Cross multiply
   13,422.88x = 18,513.31 × 9,119.30
4. Step 4: Simplify right side
   13,422.88x = 168,828,427.88
5. Step 5: Solve for x
   x = 168,828,427.88/13,422.88
6. Step 6: Final answer
   x = 12,577.66