Finding the Fourth Proportional to 15,854.30, 21,878.88 and 9,139.89

Step by Step Solution

1. Step 1: Write the proportion equation
   15,854.30 : 21,878.88 = 9,139.89 : x
2. Step 2: Convert to fraction form
   15,854.30/21,878.88 = 9,139.89/x
3. Step 3: Cross multiply
   15,854.30x = 21,878.88 × 9,139.89
4. Step 4: Simplify right side
   15,854.30x = 199,970,556.52
5. Step 5: Solve for x
   x = 199,970,556.52/15,854.30
6. Step 6: Final answer
   x = 12,613.02