Alpha $=0\mathrm{.}3$

Actual demand in year $2017=750$

Forecast demand in year $2017=960$

The formula for exponential smoothing is:

Forecast for period t $=$ Alpha $*$ Actual demand in period t$-1+(1-$ Alpha$)*$ Forecast in period t$-1$

Substituting the values:

Forecast for $2018=0\mathrm{.}3*750+(1-0\mathrm{.}3)*960$

$=0\mathrm{.}3*750+0\mathrm{.}7*960$

$=225+704$

$=929$