9) Which of the following statements about building multiple regression models is true? (4) A) No...
Discuss the following statements and explain why they are true or false. (a) Increasing the number of predictor variables will never decrease the R2. (b) Multicollinearity affects the interpretation of the regression coefficients. (c) The variance inflation factor of ˆ βj depends on the R2 of the regression of the response variable y on the predictor variable xj. (d) A high leverage point is always highly influential. (e) All criteria for the selection of the best regression equation lead to...
Which of the following statements about the t-statistic in regression is not true? a. The t-statistic provides some idea of how well a predictor predicts the outcome variable. b. The t-statistic is equal to the regression coefficient divided by its standard deviation. c. The t-statistic can be used to see whether a predictor variables makes a statistically significant contribution to the regression model. d. The t-statistic tests whether the regression coefficient, b, is equal to 0.
4) A multiple regression model is developed to predict Innovative Index, to check for the possibility of collinearity among iust the predictor variables. Data were collected on the following variables: innovative index (higher scores indicate a more innovative and creative organizational culture), job growth (in % ) and number of employees. Based on the results shown below, a regression model was run to predict innovative index based on job growth and number of employees. The regression equation is: Innovative Index...
9.) What characteristic of the outcome variable (Y) suggests that a logistic regression is a suitable methodology? a.) When the outcome is a continuous variable b.) When the outcome variable has a large variance c.) When the outcome is always positive d.) When the outcome is a dichotomous variable 10.) If, in a multiple regression of the price of a diamond against the two predictor variables, weight and color, the R2 of the regression was 0.985, then which of the...
1. In order to test whether the multiple linear regression model y bo +b,x1 + b2X2 is better than the average model (lazy model), which of the following null hypotheses is correct: a. Ho' b1 = b2 = 0 Но: B1 B2-0 с. We have a dataset Company with three variables: Sales, employees and stores. To build a multiple linear regression model using Sales as dependent variable, number of stores and number of employees as independent variables, which of the...
Need help with stats true or false questions Decide (with short explanations) whether the following statements are true or false a) We consider the model y-Ao +A(z) +E. Let (-0.01, 1.5) be a 95% confidence interval for A In this case, a t-test with significance level 1% rejects the null hypothesis Ho : A-0 against a two sided alternative. b) Complicated models with a lot of parameters are better for prediction then simple models with just a few parameters c)...
1.Which of the following statements about species-accumulation curves is TRUE? Only gamma diversity can be estimated using species-accumulation curves Species-accumulation curves are a technique to estimate alpha diversity of a relatively homogenous site Species richness will be estimated correctly using species-accumulation curves even if there are only a few samples The order in which samples are processed will not affect the precise shape of species-accumulation curve 2. Which of the following statements about beta diversity is TRUE? Beta diversity does...
peruvian.txtProblem 1 (explore the data):In this exercise use the Peruvian blood pressure data set, provided in the file peruvian.txt (A NOTE for repeat students: The data is different from the data I shared last year.). This dataset consists of variables possibly relating to blood pressures of n = 30 Peruvians who have moved from rural high altitude areas to urban lower altitude areas. The variables in this dataset are: Age, Weight, Height, Pulse, Systol and Diastol. Before reading the data into MATLAB, it can be viewed in a...
Decide (with short explanations) whether the following statements are true or false. e) In a simple linear regression model with explanatory variable x and outcome variable y, we have these summary statisties z-10, s/-3 sy-5 and у-20. For a new data point with x = 13, it is possible that the predicted value is y = 26. f A standard multiple regression model with continuous predictors and r2, a categorical predictor T with four values, an interaction between a and...
Which of the following statements regarding regression and correlation are true? (There may be more than one correct answer.) a. If the linear correlation between two variables is 0, then there is no relationship between the two variables. b. When the slope of a linear regression equation is near 0, then the linear correlation between the two variables must also be near 0. c. The average error between the actual values and the predicted values of a least squares line...