BUAL 2650 Final Exam (Chen
Yan) Exam 1, 2, and Final
Combined QUESTIONS AND
ANSWERS
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?
308,537
P(x < 36) = P(z < (36 − 40)/8) = P(z < −.5)
The area under the curve is .308537 × 1,000,000.
A standard normal distribution has a mean of_______ and standard
deviation of _________.
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.
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?
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?
Matched pairs from two dependent populations
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_________.
T
When testing the difference between two populations proportions
using large independent random samples, the ___________ test
statistic is used.
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 __________.
9
, In simple linear regression analysis, the correlation coefficient (r)
and the slope (b) _____________ have the same sign
always
All of the following are assumptions of the error terms in the simple
linear regression model except?
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.
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________________.
slope of the regression line
A simple regression analysis with 20 observations would
yield__________ degrees of freedom error and _________________
of freedom total.
18, 19
The correlation coefficient may assume any value
between____________.
-1 and 1
Yan) Exam 1, 2, and Final
Combined QUESTIONS AND
ANSWERS
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?
308,537
P(x < 36) = P(z < (36 − 40)/8) = P(z < −.5)
The area under the curve is .308537 × 1,000,000.
A standard normal distribution has a mean of_______ and standard
deviation of _________.
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.
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?
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?
Matched pairs from two dependent populations
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_________.
T
When testing the difference between two populations proportions
using large independent random samples, the ___________ test
statistic is used.
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 __________.
9
, In simple linear regression analysis, the correlation coefficient (r)
and the slope (b) _____________ have the same sign
always
All of the following are assumptions of the error terms in the simple
linear regression model except?
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.
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________________.
slope of the regression line
A simple regression analysis with 20 observations would
yield__________ degrees of freedom error and _________________
of freedom total.
18, 19
The correlation coefficient may assume any value
between____________.
-1 and 1
