BUAL 2650 FINAL EXAM (CHEN YAN) QUESTIONS
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? - Answer -308,537
A standard normal distribution has a mean of_______ and standard deviation of
_________. - Answer -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. - Answer -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? - Answer -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? - Answer -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? - Answer -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? - Answer -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_________. - Answer -T
When testing the difference between two populations proportions using large
independent random samples, the ___________ test statistic is used. - Answer -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 __________.
- Answer -9
, In simple linear regression analysis, the correlation coefficient (r) and the slope (b)
_____________ have the same sign - Answer -always
All of the following are assumptions of the error terms in the simple linear regression
model except? - Answer -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. - Answer -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________________. - Answer -slope of the regression line
A simple regression analysis with 20 observations would yield__________ degrees of
freedom error and _________________ of freedom total. - Answer -18, 19
The correlation coefficient may assume any value between____________. - Answer --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 - Answer -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 - Answer -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 - Answer -3, 16
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? - Answer -308,537
A standard normal distribution has a mean of_______ and standard deviation of
_________. - Answer -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. - Answer -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? - Answer -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? - Answer -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? - Answer -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? - Answer -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_________. - Answer -T
When testing the difference between two populations proportions using large
independent random samples, the ___________ test statistic is used. - Answer -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 __________.
- Answer -9
, In simple linear regression analysis, the correlation coefficient (r) and the slope (b)
_____________ have the same sign - Answer -always
All of the following are assumptions of the error terms in the simple linear regression
model except? - Answer -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. - Answer -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________________. - Answer -slope of the regression line
A simple regression analysis with 20 observations would yield__________ degrees of
freedom error and _________________ of freedom total. - Answer -18, 19
The correlation coefficient may assume any value between____________. - Answer --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 - Answer -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 - Answer -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 - Answer -3, 16
