as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
create a function to calculate the standard deviation of a set of numbers.
user
def standard_deviation(numbers): 
    avg = sum(numbers) / len(numbers)
    var = 0
    for num in numbers:
        var += (num - avg)**2
    return (var/len(numbers))**0.5
assistant