EDPSY 490A, Winter 2022 Homework 6 Chapter 6 (Part II) & Chapter 7 (20 pts) Due Feb 22 4:30pm Name: Homework Question 4 Now we are interested in testing the effectiveness of online instruction, as compared to inclass instruction, on math scores. We randomly assigned volunteer students at a local high school to either participate in an online teaching classroom or a regular (in-class) teaching classroom. At the end of the semester, all students were administered a nal math exam. We need to conduct a 2group test to see whether there is a significant difference on the math test between the two types of instruction (OnLine and InClass Teaching). Online: X1 = {2, 4, 5, 6, 8} InClass: X2 = {5, 8, 11, 12, 14} a) Identify the independent variable (IV) and dependent variable (DV). IV: DV: b) State the null and alternative hypotheses (in symbols). Null: Alternative: c) To start your calculations for the test statistic, calculate the sample: (i) size, (ii) mean, (iii) sum of squared deviations, (iv) degrees of freedom, and (v) variance. Use subscripts to help you keep your calculations organized (e.g., use X1 for the mean of the Online group and X 2 for the mean of the InClass group). GROUP 1 (Online) GROUP 2 (In-Class) EdPsy49O Winter 22 HWG, p. 5 EDPSY 490A, Winter 2022 Homework 6 Chapter 6 (Part II) & Chapter 7 (20 pts) Due Feb 22 4:30pm Name: Homework Question 4, Continued d) Now calculate the estimated pooled variance below. 6) Compare the pooled variance to the each of the group variances. What do you notice? f) What are we assuming about group variances when we use the estimated pooled variance (provide the name and denition of the assumption)? g) What would we have to do if we could not justify using the pooled variance (there are 2 things)? h) Calculate estimated standard error of the difference between means. i) Now calculate your test statistic. j) State your decision about whether the two methods of instruction differed signicantly. Use your obtained tvalue compared with the critical tvalue in your answer. k) Given your decision, what are the two possibilities that exist? EdPsy490 Winter 22 HWG, p. 6