Problem : Philly Air

$1.$

Question $1$

Consider the baggage check$-$in of a small airline called Philly Air. Check$-$in data indicates that $255$ passengers checked in from $9$ a$.$m$.$ to $10$ a$.$m$.$ Moreover, based on counting the numbers of passengers waiting in line, airport management found that the average number of passengers waiting in line was $35.$

How long did the average passenger have to wait in line, in minutes? $($number only and please input number up to the fourth decimal place ex: $0\mathrm{.}0000)$