Although the data are slightly right skewed, because of the large sample size(n=152) our inference on the mean is valid, by the Central Limit Therom. The Box Cox plot suggests a power transformation using a power, p= -0.5 would make the data more shaped like a normal distribution. The Normal Q-Q plot shows the transformed data points lying close to the straight line and the box plot of the transformed data looks symmetric with two outliers. The numerical summary of the transformed data confirms that the transformed data are symmetric (mean=1 and median=1). A Shapiro-Wilk test on the transformed data provides no evidence against the transformed data having come fro a normal distribution (P-value=0.4286).
The following is my evaluation of Table 3.1 Data: The education predictor has very low correlation with citizenship and absence measures. Citizenship is shown to be positive and absence is shown to be negative; however, they are both close to 0. On the contrary, the correlations between education and the performance and promotion potential are slightly higher than citizenship and absence, but they are still undesirably low. Out of these 4 measures, the correlation between education and promotional potential is considered to be the highest because education can definitely predict a future employee’s promotion potential. Promotion potential has a p value of <.01 which makes it statistically significant.
The confidence interval for the first group mean is thus (4.1, 13.9). Similarly for the second group, the confidence interval for the mean is (12.1, 21.9). Notice that the two intervals overlap. However, the t-statistic for comparing two means is: t= 17 − 9 2.5 2 + 2.5 2 = 2.26 which reflects that the null hypothesis, that the means of the two groups are the same, should be rejected at the α = 0.05 level. To verify the above conclusion, consider the 95 percent confidence interval for the difference between the two group means: (17 − 9 ) ± 1.96 × 2.5 2 + 2.5 2 which yields (1.09, 14.91).
Which t ratio in Table 2 represents the greatest relative or standardized difference between the pretest and 3 months outcomes? Is this t ratio statistically significant? Provide a rationale for your answer. The t ratio of 4.14 represent the greatest relative or standardized difference between the pretest and 3 months outcomes. Yes, it is significant because as indicated by the asterisk, p <0.05 is the least acceptable value for statistical significance.
However, in a Probit model the marginal effect is the defined by the coefficient multiplied by the G function. This means we are looking for the statistical significance of this combined partial effect not the statistical significance of the coefficient. This statistical significance is illustrated appendix 2.2 and we observe that resplast, weekslast, propresp and mailsyear are statistically significant at the 5% confidence level. However only the variable avggift was not statistically significant at the 5% confidence level
CASE FOUR:MEASUREMENT AND VALIDATION | 1. In Table 3.1, the traditional selection model shows a high p-value of 0.26 for education being citizenship and absence. The correlation score is 0.01, which means that education has little to no impact on the correlation between education and citizenship and absence. The interview score also has a p-value of 0.26, so this means that the interview score also does not relate to the correlation between performance and the interview. If the company is going to use the traditional selection model, it would do best by seeking out the lowest p-value with a high correlation score.
The plastic starts at T=165.58 and will curve all the way down slowly below T= 69.55. 3. Would the derivative of a function modeling the data points be increasing, decreasing, or constant? Explain your reasoning. The derivative of the function would be decreasing, because it would have a negative derivative.
| |1/10/11 |Platelets |27-Low |Due to her impaired liver function. Platelets are extremely low. MD ordered platelet
Provide a rationale for your answer. The mental health t ratio of t=-3.15 ratio indicates the largest difference between the males and females post MI in the study. This t ratio is significant since it is causing the p value to be significantly low, less than the alpha 0.05 set for the
Since 2.9134>1.2816, 1.6449 and 2.3263, I rejected H0 and accepted Ha at 1 = 0.10, 0.05, and 0.01 and concluded that the mean rating exceeds 42. Since 2.9134<3.0902, I rejected H0 at a = 0.001, and fail to conclude that the mean rating exceeds 42. c. Using the information in part b, calculate the p-value and use it to test H0 versus Ha at each of at = 10, .05, .01 and .001. Upper tail p-value for z = 2.9134 is 00018. Since 0.0018<0.10, 0.65, 0.01, I rejected H0 and accepted Ha at a = 0.10, 0.05, and 0.01 and concluded that the mean rating exceeds 42. Since 0.0018>0.001, I failed to reject H0 @ a = 0.001 and failed to conclude that the mean rating exceeds 42. d. How much evidence is there that the mean composite