You conduct a survey of 100 randomly chosen berkeley students, asking each one how often they get their hair cut. you conduct a two-tailed test using the standard value of with the null hypothesis that the mean time between haircuts in the population is 4 weeks. in which circumstance can you reject the null hypothesis? select one: a. a 95% confidence interval for the mean does not include 4 weeks. b. you calculate a t-statistic of 1.769, which lies at the 0.96 quantile of the t-distribution with 99 degrees of freedom. c. you get a p-value of 0.09 d. you should reject the null for all of the above.