You are thinking of using a t procedure to construct a 95% confidence interval for the mean of a population. you suspect the distribution of the population is not normal and may be skewed. which of the following statements is correct? a. you should not use the t procedure because the population does not have a normal distribution. b. you may use the t procedure, provided your sample size is large, say at least 40. c. you may use the t procedure because it is robust to nonnormality.