State the critical (tabled) value of t that would be used to reject the null hypothesis of equality of population means, for an independent groups t-test under the following conditions:
H1: μ1 ≠ μ2; n1 = 20, n2 = 20; α = .05
State the critical (tabled) value of t that would be used to reject the null hypothesis of equality of population means, for an independent groups t-test under the following conditions:
Hi: μ1 > μ2; n1 = 30, n2 = 30; α = .01
Suppose we wanted to test the hypothesis that a control group of cancer patients (Group 1) would report higher mean pain ratings than an experimental group receiving special massage treatments (Group 2). Assume that the pooled SD for the two groups is 6.39. Calculate the value of d (effect size).
- M1 = 78.5 SD12 = 42.1 n1 =25
- M2 = 72.1 SD22 = 39.7 n2 =25
(Keep 2 decimal places)