Variance & Standard Deviation of the list

def aad(lst):
    """
        return the average absolute deviation of the list
    """
    temp = []
    mean = sum(lst) / float(len(lst))
    for i in range(len(lst)):
        temp.append(float(abs(lst[i] - mean)))
    return sum(temp) / len(lst)

def variance(lst):
    """
        return the variance of list
    """
    temp = []
    mean = sum(lst) / float(len(lst))
    for i in range(len(lst)):
        temp.append(float(abs(lst[i] - mean))**2)
    return sum(temp) / (len(lst)-1)

def stddev(lst):
    """
        return the standard deviation of the list
    """
    return variance(lst)**0.5

b = [6, 15, 26, 15, 18, 23, 19, 32, 28, 44]

print "Average Absolute Deviation : " + str(aad(b))
print "variance : " + str(variance(b))
print "SV : " + str(stddev(b))