2. Imagine you are tutoring n = 10 children in piano lessons using a new teaching strategy called Zello!. At the end of one month of tutoring, you measure the children on their piano skills using the PSKILLS test. The test manual says the population average is = 70 points. Your sample of tutored students averaged = 76.2 points on the test, with a sample/estimated standard error of = 5 points. Find out if Zello! has a significant effect on children's piano skills. (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