Find the average mark
10,15,12,18,22,25,30,27,40,21

Asurvey of 45 teens found that they spent an average of 25.6 hours per week in front of a screen (television, computer, tablet, phone, based on the survey’s sample mean, which value could be the population mean? 2.3 hours 27.4 hours 75.3 hours 41.5 hours

I’m really confused and need your assist me with this question i’ve never been taught

Which point does not lie on the graph k(x) = 8 -3 √x a. (-64, 12) b. (125, 3) c. (343, 1) d. (8, 5)