Question

a. If r is a negative number, then b (in the line of regression ) is negative.

true or false

b.The line of regression is use to predict the theoric average value of y that we expect to occur when we know the value of x.

true or false

c. We can predict no matter the strength of the correlation coefficient.

true or false

d. The set of all possible values of r is, {r: -1< r < 1

treu or false

e. The graph of the line of regression is always satisfied by the point (0,1).

true or false

f. There are different values for the correlation coefficient for a same sample.

true or false

g. The lineal correlation coefficient is a method to determine the equation that represents the relationship between two variables.

true or false

h. All points (x, ?̂ ) are over the graph of the line of regression.

true or false

I. All points in an scatter diagram lie over the line of regression.

true or false

J. In a multiple lineal regression, there are two or more independent variables and only one dependent variable.

true or false

K. The relationship between variables x & y may be due to a third variable (stange variable)

true or false

L. a correlation of 0.03 is considered to be a null one

true or false

M.an strong correlation between two variables establishes a cause and effect relationship between them

true or false

N. a positive correlation is also known as direct

true or false

O. if r=1 then all points in the scatter diagram are over the line of regression

true or false

Answer #1

a correlation of 0.03 is considered to be a null one
true or false
an strong correlation between two variables establishes a cause
and effect relationship between them
true or false
a positive correlation is also known as direct
true or false
if r=1 then all points in the scatter diagram are over the line
of regression
true or false

A residual is:
The difference between a data point
and the regression line.
A value that can be 1 or zero.
A value that is always negative
because it is a difference
The difference between two different
lines.
The properties of r include:
r is sensitive to very high
quantities
The value of r is not affected if the
values of either variable are converted into a different scale
You must define the independent and
dependent variables
All of the...

Suppose we have the correlation coefficient for the relationship
between two variables, A and B. Determine whether each of the
following statement is true or false.
(a) The variables A and B are categorical.
(b) The correlation coefficient tells us whether A or B is the
explanatory variable.
(c) If the correlation coefficient is positive, then lower values
of variable A tend to correspond to lower values of variable
B.
(d) If the correlation between A and B is r...

Which of the following statements concerning regression and
correlation analysis is/are true?
A. If the correlation coefficient is zero, then there is no linear
relationship between the two variables.
B. A negative value for the correlation coefficient indicates that
high values of the independent variable are correlated with low
values of the dependent variable.
C. The slope coefficient for a simple linear regression model
measures the expected change in the independent variable for a unit
change in the dependent variable....

Find the equation of the regression line for the given data.
Then construct a scatter plot of the data and draw the regression
line. (Each pair of variables has a significant correlation.)
Then use the regression equation to predict the value of y for each
of the given x-values, if meaningful. The caloric content and the
sodium content (in milligrams) for 6 beef hot dogs are shown in
the table below. (a) x=170 Calories (B )x=100 calories (C) x=140
Calories...

Regression ____ (b values) indicate how much influence each
independent variable has on the dependent variable.
Regression analysis serves two main purposes: to define the
relationship between variables and to ____ values of the dependent
variable using what we know about the existing correlation between
the variables.
The coefficient of multiple determination, R^2, is interpreted
as the percentage of ____ in the dependent variable that is
explained by the independent variable.

A scatter diagram is a graph that portrays a correlation between
a ________________variable and a _______________ variable.
The _________________ of _________________ is expressed as a
percent, its value is between 0 and 100%.
In plotting paired data in a scatter diagram, the independent
variable is scaled on the __________________.
If there is absolutely no relationship between two variables,
Pearson's r will equal _____.
________________________________________
If the coefficient of correlation is 0.80, the coefficient of
determination is _____.
________________________________________
The proportion...

The regression line can never be used for prediction. True
False
The slope is the amount Y changes for every increase in X. True
False
"When you calculate a regression equation, you want the line
with the most error. " True False
"Correlation measures the linear relationship between two
variables, while a regression analysis precisely defines this line.
" True False
The predicted value based on a regression equation is a perfect
prediction. True False
What represents the intercept (the...

The proportion of explained variation is called the
__________________________________________
An assumption of linear regression states that for each value of
X, there is a group of Y values that are
statistically __________________ and normally distributed about the
regression line.
________________________________________
.
For an inverse relationship between two variables, the sign of
the correlation coefficient is __________________.
The standard error of the estimate measures the scatter or
dispersion of the observed values around a
__________________________________________________________

Find the equation of the regression line for the given data.
Then construct a scatter plot of the data and draw the regression
line. (Each pair of variables has a significant correlation.)
Then use the regression equation to predict the value of y for each
of the given x-values, if meaningful. The caloric content and the
sodium content (in milligrams) for 6 beef hot dogs are shown in
the table below.
Calories, x Sodium, y
150 420
170 470...

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