BUAL 2650 Final Exam (Chen Yan) Questions with 100%
Verified Solutions | A+ GRADED.
The mean life of a pair of shoes is 40 months with a standard deviation of 8 months. If the life of
the shoes is normally distributed, how many pairs of shoes out of one million will need
replacement before 36 months? correct answers 308,537
A standard normal distribution has a mean of_______ and standard deviation of _________.
correct answers Zero, One
The area under the normal curve between z=0 and z=1 is_________ the area under the normal
curve between z=1 and z=2. correct answers greater than
A new company is in the process of evaluating its customer service. The company offers two
types of sales: (1) internet sales and (2) store sales. The marketing research manager believes that
the internet sales are more than 10 percent higher than store sales. The null hypothesis would be?
correct answers P (internet)- P (store) <= .10
In order to test the effectiveness of a drug called XZR designed to reduce cholesterol level, the
cholesterol levels of 9 heart patients are measured before they are given the drug. The same 9
patients use XZR for two continuous months. After two months of continuous use, the
cholesterol levels are measured again. The comparison of cholesterol levels before versus after
administering the drug is an example of testing the difference between? correct answers Matched
pairs from two dependent populations
In testing the difference between the means of two normally distributed populations using
independent random samples with equal variances, the correct test statistic to use is? correct
answers T statistic
A new company is in the process of evaluating its customer service. The company offers two
types of sales: (1) internet sales and (2) store sales. The marketing research manager believes that
the internet sales are more than 10 percent higher than store sales. The alternative hypothesis for
this problem would be stated as? correct answers P (internet)- P (store) >.10
When testing a hypothesis about the mean of mean of a population of paired differences in which
two different observations are taken on the same units, the correct test statistic to use
is_________. correct answers T
When testing the difference between two populations proportions using large independent
random samples, the ___________ test statistic is used. correct answers Z
If we are testing the hypothesis about the mean of a population of paired differences with
samples of n1=10, n2=10, the degrees of freedom for the t statistic is __________. correct
answers 9
, In simple linear regression analysis, the correlation coefficient (r) and the slope (b)
_____________ have the same sign correct answers always
All of the following are assumptions of the error terms in the simple linear regression model
except? correct answers a) errors are normally distributed
b) error terms have a mean of zero
c) error terms have a constant variance
*d) error terms are dependent on each other*
The __________ measures the strength of the linear relationship between the dependent
variables and the independent variable. correct answers Correlation coefficient
In simple regression analysis, the quantity that gives the amount by which Y (dependent
variables) changes for a unit change in X (independent variable) is called the________________.
correct answers slope of the regression line
A simple regression analysis with 20 observations would yield__________ degrees of freedom
error and _________________ of freedom total. correct answers 18, 19
The correlation coefficient may assume any value between____________. correct answers -1
and 1
For the same set of observations on a specified dependent variable, two different indepdent
variables were used to develop two separate simple linear regression models. Based on the
results we can conclude that
Model 1: r^2= 0.92, s= 1.65
Model 2: r^2= 0.85, s= 1.91 correct answers A prediction based on model 1 is better than a
prediction based on model 2 (the larger the r^2 the better the prediction model)
The following results were obtained as part of a simple regression analysis:
r^2= .9162
F statistic from F table= 3.59
Calculated value of F from anova table= 81.87
a=.05
p-value=.000
The null hypothesis of no linear relationship between the dependent variable and the independent
variable correct answers is rejected
A multiple regression analysis with 20 observations on each of three independent variables and
the dependent variables would yield ____________ and __________ degrees of freedom,
respectively, for regression (explained) and error correct answers 3, 16
Verified Solutions | A+ GRADED.
The mean life of a pair of shoes is 40 months with a standard deviation of 8 months. If the life of
the shoes is normally distributed, how many pairs of shoes out of one million will need
replacement before 36 months? correct answers 308,537
A standard normal distribution has a mean of_______ and standard deviation of _________.
correct answers Zero, One
The area under the normal curve between z=0 and z=1 is_________ the area under the normal
curve between z=1 and z=2. correct answers greater than
A new company is in the process of evaluating its customer service. The company offers two
types of sales: (1) internet sales and (2) store sales. The marketing research manager believes that
the internet sales are more than 10 percent higher than store sales. The null hypothesis would be?
correct answers P (internet)- P (store) <= .10
In order to test the effectiveness of a drug called XZR designed to reduce cholesterol level, the
cholesterol levels of 9 heart patients are measured before they are given the drug. The same 9
patients use XZR for two continuous months. After two months of continuous use, the
cholesterol levels are measured again. The comparison of cholesterol levels before versus after
administering the drug is an example of testing the difference between? correct answers Matched
pairs from two dependent populations
In testing the difference between the means of two normally distributed populations using
independent random samples with equal variances, the correct test statistic to use is? correct
answers T statistic
A new company is in the process of evaluating its customer service. The company offers two
types of sales: (1) internet sales and (2) store sales. The marketing research manager believes that
the internet sales are more than 10 percent higher than store sales. The alternative hypothesis for
this problem would be stated as? correct answers P (internet)- P (store) >.10
When testing a hypothesis about the mean of mean of a population of paired differences in which
two different observations are taken on the same units, the correct test statistic to use
is_________. correct answers T
When testing the difference between two populations proportions using large independent
random samples, the ___________ test statistic is used. correct answers Z
If we are testing the hypothesis about the mean of a population of paired differences with
samples of n1=10, n2=10, the degrees of freedom for the t statistic is __________. correct
answers 9
, In simple linear regression analysis, the correlation coefficient (r) and the slope (b)
_____________ have the same sign correct answers always
All of the following are assumptions of the error terms in the simple linear regression model
except? correct answers a) errors are normally distributed
b) error terms have a mean of zero
c) error terms have a constant variance
*d) error terms are dependent on each other*
The __________ measures the strength of the linear relationship between the dependent
variables and the independent variable. correct answers Correlation coefficient
In simple regression analysis, the quantity that gives the amount by which Y (dependent
variables) changes for a unit change in X (independent variable) is called the________________.
correct answers slope of the regression line
A simple regression analysis with 20 observations would yield__________ degrees of freedom
error and _________________ of freedom total. correct answers 18, 19
The correlation coefficient may assume any value between____________. correct answers -1
and 1
For the same set of observations on a specified dependent variable, two different indepdent
variables were used to develop two separate simple linear regression models. Based on the
results we can conclude that
Model 1: r^2= 0.92, s= 1.65
Model 2: r^2= 0.85, s= 1.91 correct answers A prediction based on model 1 is better than a
prediction based on model 2 (the larger the r^2 the better the prediction model)
The following results were obtained as part of a simple regression analysis:
r^2= .9162
F statistic from F table= 3.59
Calculated value of F from anova table= 81.87
a=.05
p-value=.000
The null hypothesis of no linear relationship between the dependent variable and the independent
variable correct answers is rejected
A multiple regression analysis with 20 observations on each of three independent variables and
the dependent variables would yield ____________ and __________ degrees of freedom,
respectively, for regression (explained) and error correct answers 3, 16
