Please help me with this math problem urgent

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

If the value of cos330°is√3/2 then find cos 165°.

Segment wx is shown explain how you would construct a perpendicular bisector of wx using a compass and a straightedge