A restaurant is improving its processes, and is currently focusing on the final bill presented to customers. The manager samples $50$ bills per day for $12$ days, and checks to see how many are incorrect using a z$-$value of $3.$

Day

$1$

$2$

$3$

$4$

$5$

$6$

$7$

$8$

$9$

$10$

$11$

$12$

Incorrect Bills

$1$

$3$

$2$

$1$

$4$

$8$

$2$

$1$

$1$

$3$

$1$

$4$