Ekonomisk statistik II flervalsfrågor

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• The number of degrees of freedom for the appropriate chi-squared distribution in a test of independence is number of rows minus 1 times number of columns minus 1
• The degrees of freedom for a contingency table with 12 rows and 12 columns is 121
• The degrees of freedom for a contingency table with 6 rows and 3 columns is 10
• A regression analysis between sales (Y in €1000) and advertising (X in euros) resulted in the following equation = 30, 000 + 4 x increase of €1 in advertising is associated with an increase of €4, 000 in sales
• Regression analysis is a statistical procedure for developing a mathematical equation that describes how one dependent and one or more independent variables are related
• In a simple regression analysis (where Y is a dependent and X an independent variable), if the Y intercept is positive, then None of these alternatives is correct
• In regression analysis, the variable that is being predicted is the Dependent variable
• The equation that describes how the dependent variable (Y) is related to the independent variable (X) is called The regression model
• In regression analysis, the independent variable is Used to predict the dependent variable
• Larger values of r2 imply that the observations are more closely grouped about the least squares line
• In a regression model involving more than one independent variable, which of the following tests must be used in order to determine if the relationship between the dependent variable and the set of independent variables is significant? F test
• Correlation analysis is used to determine the strength of the relationship between the dependent and the independent variables
• If the coefficient of determination is equal to 1, then the coefficient of correlation can be either -1 or +1
• In a regression analysis, the variable that is being predicted is the dependent variable
• In regression analysis, if the independent variable is measured in kgs, the dependent variable can be any units
• If the coefficient of correlation is a positive value, then the slope of the regression line Must also be positive
• If two variables, X and Y, have a good linear relationship then there may or may not be any casual relationship between X and Y
• A least squares regression line may be used to predict a value of y if the corresponding x value is given
• In regression analysis if the dependent variable is measured in euros, the independent variable can be any units
• If there is a very weak correlation between two variables then the coefficient of correlation must be none of these alternatives is correct
• In regression analysis, an outlier is an observation whose Residual is much larger than the rest of the residual values
• A variable that takes on the values of 0 or 1 and is used to incorporate the effect of qualitative variables in a regression model is called A dummy variable
• In regression analysis, the response variable is the Dependent variable
• A multiple regression model has More than one independent variable
• A measure of goodness of fit for the estimated regression equation is the Multiple coefficient of determination
• In multiple regression analysis, the general linear model can be used to accommodate curvilinear relationships between the independent variables and dependent variable
• Serial correlation is The same as autocorrelation
• The joint effect of two variables acting together is called Interaction
• A variable such as Z, whose value is Z = X1X2 is added to a general linear model in order to account for potential effects of two variables X1 and X2 acting together. This type of effect is Called interaction
• All the variables in a multiple regression analysis None of these alternatives is correct
• The correlation in error terms that arises when the error terms at successive points in time are related is termed Autocorrelation
• The time series component that reflects variability during a single year is called Seasonal
• The time series component that reflects variability due to natural disasters is called Irregular
• The time series component that reflects gradual variability over a long time period is called A trend
• If data for a time series analysis is collected on an annual basis only, which component may be ignored? Seasonal
• A group of observations measured at successive time intervals is known as A time series
• A method of smoothing a time series that can be used to identify the combined trend/cyclical component is The moving average
• A method that uses a weighted average of past values for arriving at smoothed time series values is known as An exponential smoothing
• The level of measurement that allows for the rank ordering of data items is Ordinal measurement
• The labelling of parts as "defective" or "non-defective" is an example of Nominal data
• n a questionnaire, respondents are asked to mark their marital status, Marital status is an example of the Nominal scale
• The scale of measurement that is used to rank order the observations for a variable is called the Ordinal scale
• The speed of a car is an example of a variable that uses the Ratio scale
• Statistical methods that generally require very few, if any, assumptions about the population distribution are known as Non-parametric
• The Spearman rank-correlation coefficient is A correlation measure based on rank-ordered data for two variables
• A non-parametric test for the equivalence of two populations would be used instead of a parametric test for the equivalence of the population parameters if No information about the population distributions is available
• A target population is The population for which inferences are to be made
• The entity on which data are collected is the element
• Stratified random sampling is a method of selecting a sample in which the population is first divided into strata, and then random samples are drawn from each stratum
• The error that occurs because a sample, and not the entire population, is used to estimate a population parameter is a Sampling error
• A sample selected in such a manner that each sample of size n has the same probability of being selected is a simple random sample

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