Exam 19: Correlation Analysis and Regression Analysis

The larger the beta coefficient value, the stronger the effect of that variable upon the dependent variable.

When an understanding of the relationship between X and Y is the motivation behind data analysis, the estimate of the parameter is of primary importance.

The degree of linear association between two intervally scaled variables is measured by a) Pearson correlation coefficient b) significance level c) analysis of variance d) β

In a scatter diagram, the sample correlation value is 1 if,

Regression is an analysis of dependence technique since it involves a dependent variable as the focus of analysis.

If the parameter is zero, the value of b must also always be zero.

Snow Belt Airlines weighed the baggage of 100 passengers and found the mean weight to be 34.2 pounds with a standard deviation of 14 pounds.What is the 95% confidence interval for the actual weight of the baggage? Round Z to the nearest whole number) a) 20.0 - 48.2 b) 32.8 - 35.6 c) 31.4 - 37.0 d) 0.0 - 50.0

Correlation analysis provides a measure of the strength of association between two variables, but tells us nothing about the nature of the relationship between them

Although the least-squares regression line provides a reasonable fit of the data points, there are some deviations in the sample data about the line.

Which of the following is not a property of the product moment correlation coefficient?

In the expression Ŷ = 7.26 + 28.9 X, the estimated value of = 28.9 and the estimated value of β = 7.26.

The Pearson correlation coefficient measures the degree to which there is a linear association between two intervally scaled variables.

Which one of the following is the same as standard deviation of regression coefficient? a) sum of squares of errors b) standard error c) predicted value d) standard error of the estimate

A least squares criterion minimizes the squared vertical deviations from the regression line.

If a variable that is excluded from the model is correlated with an independent variable in the model, the regression coefficient will reflect the impact of the excluded variable on the dependent variable.

To examine the association between two variables after controlling for the other variables the researcher should use a) bivariate correlation b) partial correlation c) product moment correlation d) simple correlation

The unexplained variation in Y is estimated by n Y_i - Ŷ₁)² i=1

A regression model can be used to accurately predict the level of a dependent variable, given extreme values of an independent variable.

If you tested a null hypothesis on problem 7, and accepted it, the probability of Type I error would be a) .95 b) .50 c) .10 d) zero

An independent variable which takes a small number 3 or 4) of discrete values is often termed a dummy variable.