Finding the Fourth Proportional to 15,399.69, 21,251.46 and 8,685.37

Step by Step Solution

1. Step 1: Write the proportion equation
   15,399.69 : 21,251.46 = 8,685.37 : x
2. Step 2: Convert to fraction form
   15,399.69/21,251.46 = 8,685.37/x
3. Step 3: Cross multiply
   15,399.69x = 21,251.46 × 8,685.37
4. Step 4: Simplify right side
   15,399.69x = 184,576,852.27
5. Step 5: Solve for x
   x = 184,576,852.27/15,399.69
6. Step 6: Final answer
   x = 11,985.75