Quiz 9 (10) Flashcards
(25 cards)
A data point (observation) that does not fit the trend shown by the remaining data is called a(n)
a. point estimate
b. residual
c. outlier
d. None of these answers are correct
c. Outlier
At least squares regression line
a. can only be determined if a good linear relationship exists between x and y
b. may be used to predict a value of y if the corresponding x value is given
c. implies a cause-effect relationship between x and y
d. All of these answers are correct
b. may be used to predict a value of y if the corresponding x value is given
A measure of strength of the relationship between two variables is the
a. coefficent of determination
b. correlation coefficent
c. slope b1 of the estimated regression line
d. standard error of the estimate
b. correlation coefficent
A procedure used for finding the equation of a straight line that provides the best approximation for the relationship between the indepent and dependent variables is the
a. most squares method
b. least squares method
c. means squres method
d. correlation analysis
b. least squares method
The regression analysis between sales (y in $1000) and advertising (x in dollars) resulted in the following equaltion
= 50,000 + 6x
The above equation implies that an
a. increase of $6 in advertising is associated with an increase of $6,000 in sales
b. increase of $1 in advertising is associated with an increase of $56,000 in sales
c. increase of $1 in advertising is associated with an increase of $6 in sales
d. increase of $1 in advertising is associated with an increase of $6,000 in sales
d. increase of $1 in advertising is associated with an increase of $6,000 in sales
Compared to the confidence interval estimate for a particular value of y (in a linear regression model), the interval estimate for an average value of y wil be
a. the same
b. Not enough information is given
c. wider
d. narrower
d. narrower
Data points having high leverage are often
a. sum of squares error
b. residuals
c. influential
d. None of the other answers are correct
c. influential
A regression analysis resulted in the followign information regarding a dependent variable (y) and an independent variable (x)
n = 10
Ex = 55
Ey = 55
Ex^2 = 385
Ey^2 = 385
Exy = 220
The point estimate of y when x = 20 is
a. -9
b. 0
c. 9
d. 31
a. -9
A regression analysis resulted in the followign information regarding a dependent variable (y) and an independent variable (x)
n = 10
Ex = 55
Ey = 55
Ex^2 = 385
Ey^2 = 385
Exy = 220
The sample correlation coefficient equals
a. 0
b. -0.5
c. +1
d. -1
d. -1
You are given the following information about y and x
y. x
Dependent variable. Independent Variable
5. 15
7. 12
9. 10
1. 7
The least squares estimate of b0 equals
a. -1.3
b. 21.4
c. -7.647
d. 16.41176
d. 16.41176
The following information regarding a dependent variable (Y) and an independent variable (X) is provided
Y. X
4 2
3. 1
4. 4
6. 3
8. 5
At least squares estimate of the slope is
a. 3
b. 2
c. 1
d. 4
c.1
The following information regarding a dependent variable (Y) and an independent variable (X) is provided
Y. X
4 2
3. 1
4. 4
6. 3
8. 5
The coefficient of correlation is
a. 0.7906
b. 0.625
c. -0.7906
d. 0.375
a. 0.7906
You are given the following information about y and x
y x
Dependent Variable Independent Variable
12. 4
3. 6
7. 2
6. 4
At least squares estimate of b1 equals
a. 1
b. 11
c. -1
d. -11
c. -1
If the coefficent of correlation is a negative value, then the coefficient of determination
a. must be postitve
b. must also be negative
c. can be either negative or positive
d. must be zero
a. must be positive
If the coefficient of determination is 0.81, the coefficient of correlation
a. None of these answers are correct
b. must be 0.9 or -0.9
c. be a 0.6561
d. must be positive
b. must be 0.9 or -0.9
If the coefficient of determination is equal to 1, then the coefficient of correlation
a. must also be equal to 1
b. can be any value between -1 to +1
c. must be -1
d. can be either -1 or +1
d. can be either -1 or +1
In a regression analysis if r^2=1, then
a. SSR = SST
b. SSE = SST
c. SSE = 1
d. SSR = SSE
a. SSR = SST
In a regression analysis if SST = 500 and SSR = 300, then the coefficient of determination is
a. 0.6000
b. 0.3750
c. 1.6666
d. 0.1666
a. 0.6000
In a regression analysis if SST = 4500 and SSE = 1575, then the coefficient of determination is
a. 0.65
b. 0.45
c. 0.35
d. 2.85
a. 0.65
In regression analysis if the department variable is measured in dollars, the independent variable
a. can be any units
b. must be in some unit of currency
c. must also be in dollars
d. can not be in dollars
a. can be any units
In regression analysis, which of the following is not a required assumption about the error term E?
a. The expected value of the error term is zero
b. All are required assumptions about the error term
c. The values of the error term are independent
d. The variance of the error term is the same for all the values od x
b. all are required assumptions about the error term
It is possible for the coefficient of determination to be
a. All of these answers are correct, depending on the situation under consideration
b. less than zero
c. larger than 1
d. less than one
d. less than one
The equation that describes how the dependent variable (y) is related to the independent variable (x) is called
a. the regression model
b. correlation analysis
c. the correlation model
d. None of these answers is correct
a. the regression model
The proportion of the variation in the dependent variable y that is explained by the estimated regression equation is measured by the
a. correlation coefficient
b. standard error of the estimate
c. confidence interval estimate
d. coefficient of determination
d. coefficient of determination
