Math 3229 Sec. 001 Final Exam
Due Date: 12/14/2011 at 5:00pm
Part I – TURE/FALSE
T 1. An economist is interested in predicting the unemployment rate based on
gross domestic
product. Since the economist is interested in predicting unemployment, the
independent
variable is gross domestic product.
F 2. In regression analysis, there is no difference in the width of a confidence
interval and the
width of a predictor interval.
T 3. A confidence interval is narrower than a prediction interval because a
confidence interval
estimates a mean Y for a given X.
T 4. When analyzing data with regression, a transformation is necessary when the
relationship
between the dependent and independent variables is linear.
F 5. The regression equation is used to estimate a value of the dependent variable
Y based on a
selected value of the independent variable X.
F 6. A regression equation found using the least squares principle is the best-fitting
line
because the sum of the squares of the vertical deviations between the actual and
estimated
values is minimized.
T 7. The technique used to measure the strength of the relationship between two
variables
using the coefficient of correlation and the coefficient of determination is called
regression analysis.
F 8. The basic question in testing the significance of _ (rho) is to make a statistical
inference
about the true relationship between two variables.
F 9. To test the significance of Pearson's r, we use the standard normal z
distribution.
T 10. The coefficient of determination is the proportion of total variation in Y that is
explained
by X.
Part II – Multiple Choices
1. What can we conclude if the coefficient of determination is 0.94?
C) 94% of total variation of one variable is explained by variation in the other variable.
2. What is the range of values for the coefficient of determination?
D) 0% to 100% inclusive
