Finding the Fourth Proportional to 21,158.43, 31,739.24 and 7,118.49

Step by Step Solution

1. Step 1: Write the proportion equation
   21,158.43 : 31,739.24 = 7,118.49 : x
2. Step 2: Convert to fraction form
   21,158.43/31,739.24 = 7,118.49/x
3. Step 3: Cross multiply
   21,158.43x = 31,739.24 × 7,118.49
4. Step 4: Simplify right side
   21,158.43x = 225,935,462.55
5. Step 5: Solve for x
   x = 225,935,462.55/21,158.43
6. Step 6: Final answer
   x = 10,678.27