Finding the Fourth Proportional to 15,854.71, 21,874.54 and 9,139.42

Step by Step Solution

1. Step 1: Write the proportion equation
   15,854.71 : 21,874.54 = 9,139.42 : x
2. Step 2: Convert to fraction form
   15,854.71/21,874.54 = 9,139.42/x
3. Step 3: Cross multiply
   15,854.71x = 21,874.54 × 9,139.42
4. Step 4: Simplify right side
   15,854.71x = 199,920,608.37
5. Step 5: Solve for x
   x = 199,920,608.37/15,854.71
6. Step 6: Final answer
   x = 12,609.54