1. The symbol that represents the equation of the sample regressions line is:
2. The slope of the true regression line is given by:
3. Give the regression equation
y = 3 + 7x
The most central value in a confidence interval for x = 4 is:
a) 4
b) 31
c) 7
d) 3
4. Which of the following is true for the method of least squares?
a) It allows us to fit a straight line or a quadratic to a set of data
b) It should only be used if all datra points fall on a straight line
c) It requires that the sum of the vertical deviations from the points to the line be minimized
d) It should only be used if the relationship between the two variables is reasonable close to linear
5. Find r for the data shown below.
X 0 1 2 3 4
Y 25 18 16 12 9 Select the correct answer. The choices are rounded to the nearest thousandth.
a) 0.932
b) 0.981
c) 0.883
d) 0.952
6. The correlation coefficient is equal to:
a) the total variation
b) the unexplained variation
c) one minus the proportion of unexpalined variation
d) the square root of the explained variation
7. The statistic that measures the relationship between variables is called:
a) y-intercept
b) standard error of estiamate
c) standard deviation
d) correlation coefficient
8. The symbol used to indicate the y values of points on a least-squares regression line is:
9. In regression analysis, the quantity that gives the amount by which y changes for a unit change in x is called the:
a) y-intercept
b) standard error of estimate
c) slope
d) standard deviation
10. The methods of regression analysis could be appled to which of the following data sets:
a) The heights of 100 high school students
b) The SAT scores for students at two different schools
c) The heights and the weights of 100 high school students
d) The incomes of 1,000 adults in the U.S.