Finding the Fourth Proportional to 21,005.94, 31,513.59 and 9,161.63

Step by Step Solution

1. Step 1: Write the proportion equation
   21,005.94 : 31,513.59 = 9,161.63 : x
2. Step 2: Convert to fraction form
   21,005.94/31,513.59 = 9,161.63/x
3. Step 3: Cross multiply
   21,005.94x = 31,513.59 × 9,161.63
4. Step 4: Simplify right side
   21,005.94x = 288,715,856.59
5. Step 5: Solve for x
   x = 288,715,856.59/21,005.94
6. Step 6: Final answer
   x = 13,744.48