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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def scale_joint_sfs(s):
 """Scale a joint site frequency spectrum. Parameters s : array_like, int, shape (n1, n2) Joint site frequency spectrum. Returns ------- joint_sfs_scaled : ndarray, int, shape (n1, n2) Scaled joint site frequency spectrum. """


    i = np.arange(s.shape[0])[:, None]
    j = np.arange(s.shape[1])[None, :]
    out = (s * i) * j
    return out