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**jennagreer** For relatively small sample sizes such as 20, when given a sample mean and sample standard deviation, and only knowing that the variable is approximately normally distributed but the true standard deviation is unknown, can we create a t or Z statistic? What is more important in assuming normality, the sample size or knowing a standard deviation? Does the answer change based upon whether the mean and standard deviation that might be used for comparison in hypothesis testing are known and are normal? Thanks, Jenna