Finding the Fourth Proportional to 15,870.69, 21,901.55 and 8,797.05

Step by Step Solution

1. Step 1: Write the proportion equation
   15,870.69 : 21,901.55 = 8,797.05 : x
2. Step 2: Convert to fraction form
   15,870.69/21,901.55 = 8,797.05/x
3. Step 3: Cross multiply
   15,870.69x = 21,901.55 × 8,797.05
4. Step 4: Simplify right side
   15,870.69x = 192,668,986.44
5. Step 5: Solve for x
   x = 192,668,986.44/15,870.69
6. Step 6: Final answer
   x = 12,139.93