The life spans of a species of fruit fly have a$$ bell$-$shaped distribution, with a mean of $35$ days and a standard deviation of $4$ days.

$($a$)$ The life spans of three randomly selected fruit flies are $36$days$,34$days$,$ and $46$ days. Find the$$ z$-$score that corresponds to each life span. Determine whether any of these life spans are unusual.

$($b$)$ The life spans of three randomly selected fruit flies are $43$days$,39$days$,$ and $27$ days. Using the Empirical$$ Rule, find the percentile that corresponds to each life span.