Finding the Fourth Proportional to 21,238.71, 31,857.34 and 5,443.90

Step by Step Solution

1. Step 1: Write the proportion equation
   21,238.71 : 31,857.34 = 5,443.90 : x
2. Step 2: Convert to fraction form
   21,238.71/31,857.34 = 5,443.90/x
3. Step 3: Cross multiply
   21,238.71x = 31,857.34 × 5,443.90
4. Step 4: Simplify right side
   21,238.71x = 173,428,173.23
5. Step 5: Solve for x
   x = 173,428,173.23/21,238.71
6. Step 6: Final answer
   x = 8,165.66