$10-$ Using the data shown, calculate the forecast for period $7$ using a four$-$period moving average.

Day $1$: rolls sold: $50$

Day $2$: rolls sold: $50$

Day $3$: rolls sold: $48$

Day $4$: rolls sold: $60$

Day $5$: rolls sold: $53$

Day $6$: rolls sold: $60$

Multiple choice:

$-55\mathrm{.}25$

$-43\mathrm{.}25$

$-60$

$-57\mathrm{.}75$