Four different forecasting models, W$,$ X$,$ Y$,$ and Z$,$ have been developed for forecasting demand. Which forecasting model is the least accurate based on the information given in the table below?

w$=8\mathrm{.}1$

x$=9\mathrm{.}2$

y$=8\mathrm{.}7$

z$=7\mathrm{.}8$

W

X

Y

Z