i have a stat test please tell me when to use each formula like keywords to look out for thank you

Confidence interval Estimation - xZ2n or xZ2ns or xt2,n1ns - n(e2z)2 or n(ezS)2 - (x1x2)z2n112+n222 - (x1x2)Z2n1s12+n2s22 - (x1x2)t2,vspn11+n21 sp=n1+n22(n11)s12+(n21)s22 \& v=n1+n12 - (x1x2)t2,vn1s12+n2s22 v=n11(n1s12)2+n21(n2s22)2(n1s12+n2s22)2 - p^Z2np^(1p^) - n(e22)2p^(1p^) or n41(eZ)2 - (p^1p^2)z2n1p^1(1p^1)+n2p^2(1p^2)