How do i work this question out? What is the step by step computation? any reference to the Jurafsky book $($Speech and Language Processing$)$would be great

$($f$)$ The likelihood probabilities for each word given each POS tag are:

plane$/$NN $1\mathrm{.}0,$ flying$/$VBG $0\mathrm{.}6667,$ is$/$VBZ $0\mathrm{.}3333,$ stressful$/$JJ $1\mathrm{.}0$

flying$/$VBG $0\mathrm{.}3333,$ planes$/$NNS $0\mathrm{.}6667,$ are$/$VBP $0\mathrm{.}3333,$ dangerous$/$JJ $0\mathrm{.}6667$

VPRP $0\mathrm{.}25,$ saw$/$vBD $0\mathrm{.}25,$ Lauren$/$NNP $0\mathrm{.}25,$ flying$/$VBG $0\mathrm{.}25,$ planes$/$NNS $0\mathrm{.}25$

She$/$PRP $0\mathrm{.}5,$ planes$/$NNS $0\mathrm{.}5,$ doors$/$NNS $0\mathrm{.}5$