Finding the Fourth Proportional to 15,685.68, 21,648.42 and 9,719.04

Step by Step Solution

1. Step 1: Write the proportion equation
   15,685.68 : 21,648.42 = 9,719.04 : x
2. Step 2: Convert to fraction form
   15,685.68/21,648.42 = 9,719.04/x
3. Step 3: Cross multiply
   15,685.68x = 21,648.42 × 9,719.04
4. Step 4: Simplify right side
   15,685.68x = 210,401,859.92
5. Step 5: Solve for x
   x = 210,401,859.92/15,685.68
6. Step 6: Final answer
   x = 13,413.63