def find_correlation(x,y,cov):
    """ The purpose of this function is to calculate the correlation value of a graph.
    Attributes:
        - x(float): std deviation value of x value column
        - y(float): std deviation value of y value column
        - cov(float): covalent value of graph
    Returns:
        - correlation(float): the correlation value of a graph.
    """
    return round((cov / (x * y)),2)