Dalitz analysis of<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>B</mml:mi><mml:mo>→</mml:mo><mml:mi>K</mml:mi><mml:msup><mml:mi>π</mml:mi><mml:mo>+</mml:mo></mml:msup><mml:msup><mml:mi>ψ</mml:mi><mml:mo>′</mml:mo></mml:msup></mml:math>decays and the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Z</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mn>4430</mml:mn><mml:msup><mml:mo stretchy="false">)</mml:mo><mml:mo>+</mml:mo></mml:msup></mml:math>

From a Dalitz plot analysis of $B\ensuremath{\rightarrow}K{\ensuremath{\pi}}^{+}{\ensuremath{\psi}}^{\ensuremath{'}}$ decays, we find a signal for $Z(4430{)}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\psi}}^{\ensuremath{'}}$ with a mass $M=({4443}_{\ensuremath{-}12\ensuremath{-}13}^{+15+19})\text{ }\text{ }\mathrm{MeV}/{c}^{2}$, width $\ensuremath{\Gamma}=({107}_{\ensuremath{-}43\ensuremath{-}56}^{+86+74})\text{ }\text{ }\mathrm{MeV}$, product branching fraction $\mathcal{B}({\overline{B}}^{0}\ensuremath{\rightarrow}{K}^{\ensuremath{-}}Z(4430{)}^{+})\ifmmode\times\else\texttimes\fi{}\mathcal{B}(Z(4430{)}^{+}\ensuremath{\rightarrow}{\ensuremath{\pi}}^{+}{\ensuremath{\psi}}^{\ensuremath{'}})=({3.2}_{\ensuremath{-}0.9\ensuremath{-}1.6}^{+1.8+5.3})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}5}$, and significance of $6.4\ensuremath{\sigma}$ that agrees with previous Belle measurements based on the same data sample. In addition, we determine the branching fraction $\mathcal{B}({B}^{0}\ensuremath{\rightarrow}{K}^{*}(892{)}^{0}{\ensuremath{\psi}}^{\ensuremath{'}})=({5.52}_{\ensuremath{-}0.32\ensuremath{-}0.58}^{+0.35+0.53})\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}4}$ and the fraction of ${K}^{*}(892{)}^{0}$ mesons that are longitudinally polarized ${f}_{L}=({44.8}_{\ensuremath{-}2.7\ensuremath{-}5.3}^{+4.0+4.0})%$. These results are obtained from a $605\text{ }\text{ }{\mathrm{fb}}^{\ensuremath{-}1}$ data sample that contains $657\ifmmode\times\else\texttimes\fi{}{10}^{6}$ $B\overline{B}$ pairs collected near the $\ensuremath{\Upsilon}(4S)$ resonance with the Belle detector at the KEKB asymmetric-energy ${e}^{+}{e}^{\ensuremath{-}}$ collider.