Test the hypothesis that the treatment reduced the number of depressive symptoms. Use a one-tailed test with a = .05. z-critical V 2 value V the null hypothesis. If the researcher wants to reduce the likelihood of a Type 1 error, what should they do? The researcher should V the value of _V in order to reduce the likelihood of Type 1 error. Compute Cohen's d to estimate the size of the effect. Cohen's d = Complete the following sentence demonstrating how the results of the hypothesis test and the measure of effect size would appear in a research report. The treatment V a significant effect on depressive symptoms: V : , V V , one-tailed, V = Attempts :l:|:| Average l 7 9. Gravetter/Wallnau/Forzano, Essentials - Chapter 8 - End-ofchapter question 18 Screen time and use of social media are related to negative mental health outcomes, including suicidal thoughts (Twenge, Joiner, Rogers, & Martin, 2018). In a national survey of adolescents, the mean number of depressive symptoms was p = 2.06, o = 1.00. Suppose that a researcher recruits n = 25 participants and instructs them to visit friends or family instead of using social media. The researcher observes that the average number of depressive symptoms is M = 1.66 after the intervention. Standard Normal Distribution Mean = 0.0 Standard Deviation = 1.0 .5000 Test the hypothesis that the treatment reduced the number of depressive symptoms. Use a one-tailed test with a = .05