Compare means by t-test type conditions Single sample x,n,μo t-test s/√n Paired t-test d s, n /√n Two group t: x,, Si, n1, test Assumption (n1-1)s2+(n2-1) n normality (-1)+V-Dx(+ Equality of varianceCompare means by t-test Assumption: ▪ normality ▪ Equality of variance Single sample t-test type Paired t-test Two group t￾test conditions ,S,n,μ0 ,Sd ,n , s1 ,n1 , , s2 ,n2 x d H0 μ=μ0 μd=0 t s n x t / − 0 = s n d t d / − 0 = ) 1 1 ( ( 1) ( 1) ( 1) ( 1) 1 2 1 2 2 2 2 2 1 1 1 2 n n n n n s n s x x t  + − + − − + − − = ν n-1 n1+n2 -2 np -1 1 x 2 x