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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 _compute_mean(self, C, mag, rjb):
 """ Compute mean value according to equation 3, page 46. """

        mean = (C['c1'] +
                self._compute_term1(C, mag) +
                self._compute_term2(C, mag, rjb))
        return mean