The 95% confidence interval for the average test score for Florida students is (Round your responses to two decimal places.) Is there statistically significant evidence that Florida students perform differently than other students in the United States? The 95% confidence interval for the average test score for Florida students =990, so the null hypothesis that =990 (that Florida students have the same average performance as other students in the United States) at the 5% level. The 95% confidence interval for the change in average test score associated with the prep course is (Round your responses to two decimal places.) Is there statistically significant evidence that the prep course helped? A. Yes, because the 95% confidence interval for the change in average test score associated with the prep course does not include prepnon-prep =0. B. No, because the 95% confidence interval for the change in average test score associated with the prep course does not include prepnon- prep =18.96. C. Yes, because the 95% confidence interval for the change in average test score associated with the prep course includes prepnon-prep=18.96. D. No, because the 95% confidence interval for the change in average test score associated with the prep course includes prepnon-prep =0. Let X denote the change in the test score. The 95% confidence interval for the change in average test scores (X) is (, ). (Round your responses to two decimal places.) Is there statistically significant evidence that students will perform better on their second attempt after taking the prep course? A. Yes, because the 95% confidence interval for the change in average test scores does not include x=8.91. B. No, because the 95% confidence interval for the change in average test scores includes X=8.91. C. Yes, because the 95% confidence interval for the change in average test scores does not include =0. D. No, because the 95% confidence interval for the change in average test scores includes x=0. the sample covariance (SXY) If SX2=87.12,SY2=185.14, and SXY=118.10, then the sample correlation coefficient will be 0.81 . (Round your answer to two decimal places). Which of the following statements can be inferred from the value of the sample correlation coefficient calculated above? (Check all that apply.) 1. There is a strong linear association between X and Y. B. The points in the scatterplot lie very close to a straight line. C. There is a weak linear association between X and Y. D. The points in the scatterplot have a steep slope. Could the researcher make general inferences about the correlation between X and Y from the sample correlation value? A. Yes, because the sample correlation is a consistent estimator for the population correlation. B. No, because the sample correlation value changes from sample to sample. C. Yes, because the sample correlation is an unbiased estimator for the population correlation. D. No, because the sample correlation is not an efficient estimator for the population correlation
