Finding the Fourth Proportional to 12,780.49, 17,632.18 and 9,431.30

Step by Step Solution

1. Step 1: Write the proportion equation
   12,780.49 : 17,632.18 = 9,431.30 : x
2. Step 2: Convert to fraction form
   12,780.49/17,632.18 = 9,431.30/x
3. Step 3: Cross multiply
   12,780.49x = 17,632.18 × 9,431.30
4. Step 4: Simplify right side
   12,780.49x = 166,294,379.23
5. Step 5: Solve for x
   x = 166,294,379.23/12,780.49
6. Step 6: Final answer
   x = 13,011.58