Most commercial internet sites monitor site traffic so that they can recognize attacks by hackers, such as distributed denial of service attack $($DDoS$).$ In this attack, the hacker hijacks a collection of computers connected to the internet and has them all attempt to access the commercial site. The sudden increase in activity overloads the server and makes it impossible for legitimate users to log in$.$ The systems engineer says that during typicla use, the site gets $20$ hits per minute, on average. He didn't have any idea when asked about a standard deviation. The accompanying data show the number of hits per minute over three hours one day. Complete parts $($a$)$ and $($b$)$ below.