Using bpstudy.sav, conduct an independent samples t test in SPSS with gender as the grouping variable (male = 1; female = 2) and HR1 (heart rate) as the outcome variable. Paste the SPSS output and then report: The sample size for males ( n 1) and sample size for females ( n 2). The means for males ( M 1) and females ( M 2) on HR1. The calculated mean difference ( M 1 – M 2). The standard deviations for males ( s 1) and females ( s 2) on HR1. The Levene test (homogeneity of variance assumption) and interpretation. t, degrees of freedom, t value, and probability value. State whether or not to reject the null hypothesis. Interpret the results. Calculate Cohen's d effect size from the SPSS output and interpret it. Specifically, if the homogeneity of variance assumption is met, divide the mean difference ( M 1 – M 2) by either s 1 or s 2. Violation of the homogeneity of variance assumption requires calculation of S pooled. Homogeneity assumed: Cohen's d = ( M 1 – M 2) ÷ s 1 or Cohen's d = ( M 1 – M 2) ÷ s 2 To be comprehensive, report Cohen's d based on a calculation with s 1 and a calculation with s 2. Round the effect size to two decimal places. Interpret Cohen's d with Table 5.2 of your Warner text. Section 2: Post-hoc Power Analysis Open G*Power. Select the following options: Test family = t tests. Statistical test = Means: Difference between two independent groups (two groups). Type of power analysis = Post hoc: Compute achieved power. Tails(s) = Two. Effect size d = Cohen's d obtained from Section 1 above (using either s 1 or s 2). α err prob = standard alpha level. Sample size group 1 = n 1 from Section 1 above. Sample size group 2 = n 2 from Section 1 above. Click Calculate . Provide a screen shot of your G*Power output. Report the observed power of this post-hoc power analysis. Interpret the level of power in terms of rejecting a null hypothesis. Do you have sufficient power to reject a false null hypothesis? Interpret power in terms of committing a Type II error. Section 3: A Priori Power Analysis In G*Power, now select: Type of power analysis = A priori: Compute required sample size. Input effect size d from Section 1. Specify α err prob. Specify Power (1 - β) = .80. Set the Allocation ratio to 1 (i.e., equal sample sizes). Press Calculate. Provide a screen shot of your G*Power output. Interpret the meaning of a .80 power value. Specifically, report the estimated n 1, n 2, and total N to achieve obtain a power of .80. How many total subjects ( N ) would be needed to obtain a power of .80? Would you have expected a required N of this size? Why or why not? Next, in G*Power, change the Cohen's d effect size value obtained in Section 1 and set it to .50 (conventional "medium" effect size). Click Calculate . How many total subjects ( N) are needed to obtain a power of .80? Compare and contrast these two estimated N s. In co ...