Forecast the preceding eight years, and determine the forecast errors. $($Negative answers should be indicated by a minus sign.

Do not round intermediate calculations and rouna your final answer to $<$ decimal places.$)$

$3$

$200-512$

A$5$a

$49\mathrm{.}80$

$560$

$54\mathrm{.}60$

$57\mathrm{.}60$

$65\mathrm{.}40$

a$-3.$ Construct $2$s control limits$.($Round the final answer to $2$ decimal places.$)$