1. Imagine you have a side business selling vintage products on Amazon and decided to see if adding video demonstrations of your products would improve your daily sales. Normally, you earn an average of = $56 in a day, with a true standard error of = $8. Across n = 14 days of using video demonstrations for your products, you found that your daily earnings averaged = $79. Find out if using product demo videos has a significant effect on daily sales. (a) Who/what are the subjects in this case? __________________________________________________ (b) What is the independent variable? __________________________________________________ (c) What is the dependent variable? __________________________________________________ (d) State the null hypothesis and the alternative hypotheses in symbols. The null hypothesis: The alternative hypothesis: (e) Compute your test statistic (Zobtained if true variance is given, or t(df)obtained if true variance is not given). Circle your final answer. (f) State the corresponding critical value you will use (Zcritical or t(df)critical if true variance is not given). (g) Write a sentence that states your decision to retain or reject the null, including why you decided to retain or reject the null (compare your obtained test statistic to the critical value). (h) Write a sentence that tells me which 2 possibilities exist, given your decision