BUAL 2650- GRAMLING EXAM 2
QUESTIONS & ANSWERS(GRADED
A+)
false
Correlation does not assume or imply causation. The correlation coefficient,r, gives
the strength and direction of the relationship between two quantitative variables. -
ANSWERA significant positive correlation between X and Y implies that changes in
X cause Y to change.
monthly advertising expenditures
The variable being used to make a prediction is plotted on the x-axis of the
scatterplot.
The prediction (or response variable) is plotted on the y-axis of the scatterplot. -
ANSWERA local tire dealer wants to predict the number of tires sold each month. He
believes that the number of tires sold is a linear function of the amount of money
invested in advertising. He randomly selects 6 months of data consisting of monthly
tire sales (in thousands of tires) and monthly advertising expenditures (in thousands
of dollars). The simple linear regression equation is ŷ = 3 + 1x. The dealer randomly
selects one of the six observations, with a monthly sales value of 8,000 tires and
monthly advertising expenditures of $7,000. Which variable would be plotted on the
X axis of the scatterplot?
slope of regression line
The slope can be positive or negative based on the relationship between x and y.
The sign of the slope and the sign of the correlation coefficient, r, are always the
same. - ANSWERIn simple regression analysis, the quantity that gives the amount
by which Y (dependent variable) changes for a unit change in X (independent
variable) is called the
0
When x is equal to zero you would expect to get the value of the y intercept for y. -
ANSWERIn a simple linear regression model, the intercept term is the mean value of
y when x equals ________.
false
Correlation does not assume or predict causation or direction. The correlation
coefficient,r, gives the strength and direction of the relationship between two
quantitative variables. - ANSWERWhen using simple regression analysis, if there is
a strong correlation between the independent and dependent variables, then we can
, conclude that an increase in the value of the independent variable causes an
increase in the value of the dependent variable.
outlier
Outliers are identified as measurements that are widely separated from the other
data measurements. - ANSWERAn unusually large or small observation separated
from the rest of the data is a(n) ________.
false
This notation refers to the estimated or predicted value of the dependent variable. -
ANSWERThe notation Ŷ refers to the average value of the dependent variable Y.
y-intercept
When x is equal to 0 you would predict to get the y intercept as your y value. -
ANSWERThe ________ of the simple linear regression model is the value of y when
the mean value of x is zero.
True
The independent variable on the x axis while the dependent variable is on the y axis
of a scatterplot. - ANSWERA simple linear regression model is an equation that
describes the straight-line relationship between a dependent variable and an
independent variable.
-2000
residual = observed # tires - predicted # tires
e = y - predicted y - ANSWERA local tire dealer wants to predict the monthly sales
for number of tires sold each month. He believes tires sale is a linear function of the
amount of money invested in advertising. He randomly selects 6 months of data
consisting of monthly tire sales and monthly advertising expenditures. The simple
linear regression equation is ŷ = 3000 + 1x. The dealer randomly selects one of the
six observations, with a monthly sales value of 8,000 tires and monthly advertising
expenditures of $7,000. Calculate the value of the residual for this observation.
slope of the regression line
The slope can be positive or negative based on the relationship between x and y. -
ANSWERIn simple regression analysis, the quantity that gives the amount by which
Y (dependent variable) changes for a unit change in X (independent variable) is
called the
one unit increase
Slope can be positive or negative. - ANSWERIn a simple linear regression model,
the slope term is the change in the mean value of y associated with ________ in x.
QUESTIONS & ANSWERS(GRADED
A+)
false
Correlation does not assume or imply causation. The correlation coefficient,r, gives
the strength and direction of the relationship between two quantitative variables. -
ANSWERA significant positive correlation between X and Y implies that changes in
X cause Y to change.
monthly advertising expenditures
The variable being used to make a prediction is plotted on the x-axis of the
scatterplot.
The prediction (or response variable) is plotted on the y-axis of the scatterplot. -
ANSWERA local tire dealer wants to predict the number of tires sold each month. He
believes that the number of tires sold is a linear function of the amount of money
invested in advertising. He randomly selects 6 months of data consisting of monthly
tire sales (in thousands of tires) and monthly advertising expenditures (in thousands
of dollars). The simple linear regression equation is ŷ = 3 + 1x. The dealer randomly
selects one of the six observations, with a monthly sales value of 8,000 tires and
monthly advertising expenditures of $7,000. Which variable would be plotted on the
X axis of the scatterplot?
slope of regression line
The slope can be positive or negative based on the relationship between x and y.
The sign of the slope and the sign of the correlation coefficient, r, are always the
same. - ANSWERIn simple regression analysis, the quantity that gives the amount
by which Y (dependent variable) changes for a unit change in X (independent
variable) is called the
0
When x is equal to zero you would expect to get the value of the y intercept for y. -
ANSWERIn a simple linear regression model, the intercept term is the mean value of
y when x equals ________.
false
Correlation does not assume or predict causation or direction. The correlation
coefficient,r, gives the strength and direction of the relationship between two
quantitative variables. - ANSWERWhen using simple regression analysis, if there is
a strong correlation between the independent and dependent variables, then we can
, conclude that an increase in the value of the independent variable causes an
increase in the value of the dependent variable.
outlier
Outliers are identified as measurements that are widely separated from the other
data measurements. - ANSWERAn unusually large or small observation separated
from the rest of the data is a(n) ________.
false
This notation refers to the estimated or predicted value of the dependent variable. -
ANSWERThe notation Ŷ refers to the average value of the dependent variable Y.
y-intercept
When x is equal to 0 you would predict to get the y intercept as your y value. -
ANSWERThe ________ of the simple linear regression model is the value of y when
the mean value of x is zero.
True
The independent variable on the x axis while the dependent variable is on the y axis
of a scatterplot. - ANSWERA simple linear regression model is an equation that
describes the straight-line relationship between a dependent variable and an
independent variable.
-2000
residual = observed # tires - predicted # tires
e = y - predicted y - ANSWERA local tire dealer wants to predict the monthly sales
for number of tires sold each month. He believes tires sale is a linear function of the
amount of money invested in advertising. He randomly selects 6 months of data
consisting of monthly tire sales and monthly advertising expenditures. The simple
linear regression equation is ŷ = 3000 + 1x. The dealer randomly selects one of the
six observations, with a monthly sales value of 8,000 tires and monthly advertising
expenditures of $7,000. Calculate the value of the residual for this observation.
slope of the regression line
The slope can be positive or negative based on the relationship between x and y. -
ANSWERIn simple regression analysis, the quantity that gives the amount by which
Y (dependent variable) changes for a unit change in X (independent variable) is
called the
one unit increase
Slope can be positive or negative. - ANSWERIn a simple linear regression model,
the slope term is the change in the mean value of y associated with ________ in x.
