def normal_two_sided_bounds(probability, mu=0, sigma=1):
 tail_probability = ((1 - probability) / 2)
 upper_bound = normal_lower_bound(tail_probability, mu, sigma)
 lower_bound = normal_upper_bound(tail_probability, mu, sigma)
 return (lower_bound, upper_bound)

def normal_two_sided_bounds ( probability , mu = 0 , sigma = 1 ) : tail_probability = ( ( 1 - probability ) / 2 ) upper_bound = normal_lower_bound ( tail_probability , mu , sigma ) lower_bound = normal_upper_bound ( tail_probability , mu , sigma ) return ( lower_bound , upper_bound )
returns the symmetric bounds that contain the specified probability .