Finding the Fourth Proportional to 21,005.28, 31,498.20 and 9,321.84

Step by Step Solution

1. Step 1: Write the proportion equation
   21,005.28 : 31,498.20 = 9,321.84 : x
2. Step 2: Convert to fraction form
   21,005.28/31,498.20 = 9,321.84/x
3. Step 3: Cross multiply
   21,005.28x = 31,498.20 × 9,321.84
4. Step 4: Simplify right side
   21,005.28x = 293,621,180.69
5. Step 5: Solve for x
   x = 293,621,180.69/21,005.28
6. Step 6: Final answer
   x = 13,978.45