[Verified Answer]: Screen time and use of social media are…

Screen time and use of social media are related tonegative mental health outcomes, including suicidalthoughts (Twenge, Joiner, Rogers, & Martin, 2018).In a national survey of adolescents, the mean numberof depressive symptoms was μ = -.06, sigma =1.00.Suppose that a researcher recruits n = 25 participantsand instructs them to visit friends or family instead ofusing social media. The researcher observes that theaverage number of depressive symptoms is M = 1.66after the intervention. a. Test the hypothesis that the treatment reduced thenumber of depressive symptoms. Use a one-tailedtest with alpha = .05. b. If the researcher wants to reduce the likelihood of aType 1 error, what should they do? c. Compute Cohen’s d to estimate the size of the effect. d. W