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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_weight_std(self, C, mag):

 """
 Common part of equations 8 and 9, page 971.
 """

        if mag < 6.0:
            return C['a1']
        elif mag >= 6.0 and mag < 6.5:
            return C['a1'] + (C['a2'] - C['a1']) * ((mag - 6.0) / 0.5)
        else:
            return C['a2']