1a. Let's say we have two groups, group 1 = 9- to 15-year-old girls & group 2 = 16- to 22- year-old girls, who are given questionnaires regarding their desire to see a band live. The questionnaire was rated on a scale of 1 = no desire to see the hand to 10 = extremelj: high desire to see the band. Group 1 had a mean of 31 = 7.5 Group 2 had a mean of E; = 3.7 The sample size for each group was n1 = 10 and n; = 10 Variance for group 1 was s21 = 2.25 Variance for group 2 was s2; = 1.44 We want to know if the sample means differ from one another and decide to do an independent-samples t test. Please compute the sample statistic (aka observed value oft) by hand. Report the t statistic using three decimal places (round to the thousandths). For full credit, he sure to show all of your work. (3 points 2 points for correct answer and 1 point for showing work) Formulas: a) Pooled variance: 2 _ dflsf + dfzs SP df1 + df2 5% = pooled variance SE = variance of group 1 5% = variance of group 2 df1= degrees of freedom of group 1 (n1 1) df2= degrees of freedom of group 2 (n2 1) 13) Estimated standard error ofthe difference between means: 2 2 S_ _ = is + is 361963 n1 n2 sxr = estimated standard error of the difference between means 5% = pooled variance n1f= sample size of group 1 r12 = sample size of group 2 0) Sample statistic (aka observed value oft) tzcx(UlUz) EiEa T1 = sample mean of group 1 E = sample mean of group 2 Lil: population mean 1 Liz: population mean 2 sxr = estimated standard error of the difference between means b. What are the degrees of freedom for the independent-samples t test computed in question (a)? For full credit, he sure to show all of your work. (1 point for correct answer) Formula: gm degrees of freedom = (N1 + N 2) 2