9.3 Distribution Needed for Hypothesis Testing Sample size Test statistic (σ unknown) tc=¯X−μ0s/√n (σ known) \(Z_{c}=\frac{\overline{X}-\mu_{0}...9.3 Distribution Needed for Hypothesis Testing Sample size Test statistic (σ unknown) tc=¯X−μ0s/√n (σ known) Zc=¯X−μ0σ/√n Table \PageIndex6 Test Statistics for Test of Means, Varying Sample Size, Population Known or Unknown