Finding the Fourth Proportional to 21,003.42, 31,508.32 and 7,149.18

Step by Step Solution

1. Step 1: Write the proportion equation
   21,003.42 : 31,508.32 = 7,149.18 : x
2. Step 2: Convert to fraction form
   21,003.42/31,508.32 = 7,149.18/x
3. Step 3: Cross multiply
   21,003.42x = 31,508.32 × 7,149.18
4. Step 4: Simplify right side
   21,003.42x = 225,258,651.18
5. Step 5: Solve for x
   x = 225,258,651.18/21,003.42
6. Step 6: Final answer
   x = 10,724.86