Finding the Fourth Proportional to 11,905.81, 16,426.69 and 9,380.09

Step by Step Solution

1. Step 1: Write the proportion equation
   11,905.81 : 16,426.69 = 9,380.09 : x
2. Step 2: Convert to fraction form
   11,905.81/16,426.69 = 9,380.09/x
3. Step 3: Cross multiply
   11,905.81x = 16,426.69 × 9,380.09
4. Step 4: Simplify right side
   11,905.81x = 154,083,786.62
5. Step 5: Solve for x
   x = 154,083,786.62/11,905.81
6. Step 6: Final answer
   x = 12,941.90