D Question 9 3 pts When using the 4 step hypothesis testing method, the alternative hypothesis O is symbolized by: H1 is symbolized by: HO states that the two population means are equal O must be directional in nature (must be a one tailed test) Question 10 3 pts When a researcher knows the population mean and standard deviation for the general (untreated) raw score distribution, what type of inferential test can be used to determine the effectiveness of a treatment (the independent variable)? An inferential Z score test A one sample t test A two independent samples t test a Pearson correlation D Question 11 3 pts When a researcher rejects the null hypothesis, what does this mean? the results support the hypothesis that the independent variable (treatment) significantly altered scores the results support the hypothesis that the treatment (LV.) did not alter scores O the results support the hypothesis that there is homogeneity of variance the results support the hypothesis that more statistical power is needed