# all these functions return a single numeric value

def max(x):
    # calculates the maximum value in x
    pass


def min(x):
    # calculates the minimum value in x
    pass


def sum(x):
    # calculates the sum of all values in x
    pass


def mean(x):
    # calculates the mean average of the values in x
    pass


def sd(x):
    # calculates the standard deviation of the values in x
    pass


def range(x):
    # calculates the range of the values in x
    pass


def median(x):
    # calculates the median of the values in x
    pass


def cov(x, y):
    # calculates the covariance between the two numeric array x and y
    pass


def cor(x, y):
    # calculates the correlation between the two numeric array x and y
    pass














