EXST 2201 QUIZ 4 EXAM QUESTIONS AND ANSWERS
WITH COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
7.1
Please match the following questions with their answers for the t-equation to
convert a sample average into a standardized value
t0=¯¯¯x−μs√n
The location of the sample average (adjusted for mu): What goes in the numerator?
The spread of the sample average: What goes in the denominator?
Please choose the location and spread for the t-equation for a dependent two-
sample situation.
(50%) The location of the difference column
d−0
.
(50%) The spread of the difference column
Sd/ (sqrt)n
Please choose the location and spread for the t-equation for an independent two-
sample situation.
,(50%) The difference in the two locations
x1−x2
(50%) The two spreads combined together
√(s1^2/n1 +s2^2/n2)
What are the two most significant ways that two-sample situations differ from
one-sample situations?
(50%) There are twice as many sources of variation in the situation.
(50%) The two spreads can be the same or different.
Use the information below to determine the dependency of the situation.
An instructor teaches a large statistics course at a local university and wonders
how this semester's students will do. Before the semester starts, she randomly
samples 50 of her students and gives them a pretest. After the semester is over,
she gives the same students a post test. She calculates the difference in scores
to see how well her students did that semester.
This is a dependent two-sample situation.
Use the information below to determine the dependency of the situation.
An instructor teaches a large statistics course at a local university and wonders
how this semester's students will do. Before the semester starts, she randomly
samples 50 of her students and gives them a pretest. After the semester is over,
,she randomly samples 50 other students and gives them a post test. She
calculates the difference in scores to see how well her students did that
semester.
This is an independent two-sample situation.
Use the information below to determine the dependency of the situation.
A researcher in marital relationships wants to study the difference in opinion
between husbands and wives. To get information on this issue she randomly
selects 50 husbands and randomly selects 50 wives. She then gives them a
survey of questions designed to answer her question.
This is an independent two-sample situation between husbands and wives.
Use the information below to determine the dependency of the situation.
A nutritionist questions whether two soft drinks have the same effect on weight
gain in teenagers who consume a lot of soft drinks. To find out, she randomly
selects 50 teenagers and asks them to drink only soft drink #1 for six weeks. She
then measures the change in weight for each teenager. Next, she asks the same
teenagers to drink only soft drink #2 for six weeks, and measures the change in
weight for each teenager.
This is a dependent two-sample situation between teenagers drinking soft drinks.
What logic is used in statistics to make it possible to test for the population mean
in a dependent two-sample situation?
, Remove the dependency by subtracting the two data values to convert it to a one-
sample situation.
Why is removing the dependency a reasonable option in a dependent one-sample
situation?
Because it is both logically and mathematically correct and easy to do.
Why does a dependent two-sample situation have two sources of variation?
Because both d an Sd can vary from sample to sample.
What is the appropriate degrees of freedom to use for an independent two-sample
situation where the variances are known to be equal.
The pooled degrees of freedom.
What is the appropriate degrees of freedom to use for a independent two-sample
situation where the variances are known to be not equal.
Satterthwaite's approximate degrees of freedom if given in the problem.
If Satterthwaite's degrees of freedom is given in the problem, why use it over
Welch's degrees of freedom.
Because Satterthwaite's is a much, much better approximation than Welch's.
What is the appropriate equation for a dependent two-sample t-test.
t0 = (d-0)/ (Sd (sqrt)n)
What is the appropriate equation for an independent two-sample t-test.
t0 = (x1-x2)-0 / sqrt(s1^2/n1 + s2^2/n2)
What statistical method is used to tell if two population variances are equal, or
not equal?
Levene's Equality of Variance Test.
WITH COMPLETE SOLUTIONS VERIFIED LATEST UPDATE
7.1
Please match the following questions with their answers for the t-equation to
convert a sample average into a standardized value
t0=¯¯¯x−μs√n
The location of the sample average (adjusted for mu): What goes in the numerator?
The spread of the sample average: What goes in the denominator?
Please choose the location and spread for the t-equation for a dependent two-
sample situation.
(50%) The location of the difference column
d−0
.
(50%) The spread of the difference column
Sd/ (sqrt)n
Please choose the location and spread for the t-equation for an independent two-
sample situation.
,(50%) The difference in the two locations
x1−x2
(50%) The two spreads combined together
√(s1^2/n1 +s2^2/n2)
What are the two most significant ways that two-sample situations differ from
one-sample situations?
(50%) There are twice as many sources of variation in the situation.
(50%) The two spreads can be the same or different.
Use the information below to determine the dependency of the situation.
An instructor teaches a large statistics course at a local university and wonders
how this semester's students will do. Before the semester starts, she randomly
samples 50 of her students and gives them a pretest. After the semester is over,
she gives the same students a post test. She calculates the difference in scores
to see how well her students did that semester.
This is a dependent two-sample situation.
Use the information below to determine the dependency of the situation.
An instructor teaches a large statistics course at a local university and wonders
how this semester's students will do. Before the semester starts, she randomly
samples 50 of her students and gives them a pretest. After the semester is over,
,she randomly samples 50 other students and gives them a post test. She
calculates the difference in scores to see how well her students did that
semester.
This is an independent two-sample situation.
Use the information below to determine the dependency of the situation.
A researcher in marital relationships wants to study the difference in opinion
between husbands and wives. To get information on this issue she randomly
selects 50 husbands and randomly selects 50 wives. She then gives them a
survey of questions designed to answer her question.
This is an independent two-sample situation between husbands and wives.
Use the information below to determine the dependency of the situation.
A nutritionist questions whether two soft drinks have the same effect on weight
gain in teenagers who consume a lot of soft drinks. To find out, she randomly
selects 50 teenagers and asks them to drink only soft drink #1 for six weeks. She
then measures the change in weight for each teenager. Next, she asks the same
teenagers to drink only soft drink #2 for six weeks, and measures the change in
weight for each teenager.
This is a dependent two-sample situation between teenagers drinking soft drinks.
What logic is used in statistics to make it possible to test for the population mean
in a dependent two-sample situation?
, Remove the dependency by subtracting the two data values to convert it to a one-
sample situation.
Why is removing the dependency a reasonable option in a dependent one-sample
situation?
Because it is both logically and mathematically correct and easy to do.
Why does a dependent two-sample situation have two sources of variation?
Because both d an Sd can vary from sample to sample.
What is the appropriate degrees of freedom to use for an independent two-sample
situation where the variances are known to be equal.
The pooled degrees of freedom.
What is the appropriate degrees of freedom to use for a independent two-sample
situation where the variances are known to be not equal.
Satterthwaite's approximate degrees of freedom if given in the problem.
If Satterthwaite's degrees of freedom is given in the problem, why use it over
Welch's degrees of freedom.
Because Satterthwaite's is a much, much better approximation than Welch's.
What is the appropriate equation for a dependent two-sample t-test.
t0 = (d-0)/ (Sd (sqrt)n)
What is the appropriate equation for an independent two-sample t-test.
t0 = (x1-x2)-0 / sqrt(s1^2/n1 + s2^2/n2)
What statistical method is used to tell if two population variances are equal, or
not equal?
Levene's Equality of Variance Test.
