Table 7 Some pmfs of the new family based on different T distributions.

From: A new (T-X\(^\theta\)) family of distributions: properties, discretization and estimation with applications

Distribution of t

pmf

Sub family

Exponential

\(e^{- \alpha {x^{\theta }F(x)}}- e^{- \alpha {(x+1)^{\theta }F(x+1)}}\)

DE-\(X^{\theta }\)

Weibull

\(e^{- \left( \frac{x^{\theta }F(x)}{\beta }\right) ^{\lambda }}- e^{- \left( \frac{(x+1)^{\theta }F(x+1)}{\beta }\right) ^{\lambda }}\)

DW-X\(^{\theta }\)

Rayleigh

\(e^{- \left( \frac{x^{\theta }F(x)}{\beta }\right) ^{2}}- e^{- \left( \frac{(x+1)^{\theta }F(x+1)}{\beta }\right) ^{2}}\)

DR-X\(^{\theta }\)

Fréchet

\(e^{-\left( \frac{(x+1)^{\theta }F(x+1)}{\delta }\right) ^{-\kappa }}-e^{-\left( \frac{x^{\theta }F(x)}{\delta }\right) ^{-\kappa }}\)

DFr-X\(^{\theta }\)

Lomax

\((1+\beta x^{\theta }F(x))^{-\alpha }-(1+\beta (x+1)^{\theta }F(x+1))^{-\alpha }\)

DL-X\(^{\theta }\)

Burr

\((1+ (x^{\theta }F(x))^{\alpha })^{-\beta } -(1+ ((x+1)^{\theta }F(x+1))^{\alpha })^{-\beta }\)

DB-X\(^{\theta }\)

Log-logistic

\({1}/\left( {1+({(x+1)^{\theta }F(x+1)}/{\alpha })^{-\beta }}\right) -{1}/\left( {1+({x^{\theta }F(x)}/{\alpha })^{-\beta }}\right)\)

DLL-X\(^{\theta }\)

Gamma

\({\gamma \left( \alpha , \beta (x+1)^{\theta }F(x+1)\right) }/{\Gamma (\alpha )}-{\gamma \left( \alpha , \beta x^{\theta }F(x)\right) }/{\Gamma (\alpha )}\)

DG-X\(^{\theta }\)

Log-normal

\(\dfrac{1}{2}\left[ \Phi \left( \dfrac{\ln ((x+1)^{\theta }F(x+1))-\mu }{\sigma \sqrt{2}}\right) -\Phi \left( \dfrac{\ln (x^{\theta }F(x))-\mu }{\sigma \sqrt{2}}\right) \right]\)

DLN-X\(^{\theta }\)