Statistics Test 3 (Chapters 9, 10, 11)
The degrees of freedom for a two-way chi-square statistic are:
(r-1)(c-1)
Choose the weakest correlation:
+.12
A criminologist wonders if there is a relationship between how often people watch television news (X) and their fear of crime (Y). The researcher conducts a survey asking how many days per week do you watch the local television news and how afraid are you to walk in your own neighborhood after dark. The degree of fear is measured on a scale from 0 to 10, where 0 is "none at all" and 10 is "completely afraid." Use the following information to answer the questions. What is the Pearson correlation coefficient for this problem?
+0.118
The following six students were questioned regarding their attitudes toward the legalization of prostitution (X) and their attitudes toward the legalization of marijuana (Y). Use the following data and analysis to answer the question. What is Pearson's correlation coefficient for this data?
+0.855
Choose the strongest correlation:
-.76
The computed Pearson's correlation is:
-0.5
Before moving away to college, Lisa is warned about the high cost of parking tickets close to campus. To determine the validity of the warning, Lisa asks 10 other students at registration how long they have been a student (X) and how much they paid last year in parking tickets (Y). The data and analysis are as follows: What is Pearson's correlation coefficient for this data?
-0.809
If r = .37, the coefficient of determination is equal to:
.14
If r = .84, the coefficient of determination is equal to:
.71
The correlation between two variables that are TOTALLY unrelated would be:
0
If a = 8 and b = 3, what would be the predicted outcome () for a person with X = 6?
26
The following six students were questioned regarding their attitudes toward the legalization of prostitution (X) and their attitudes toward the legalization of marijuana (Y). Use the following data and analysis to answer the question. What is the correct number of degrees for freedom for this correlation problem?
4
If a = 3 and b = 5, a person scoring X = 8 would be predicted to have a Y score of:
43
The degrees of freedom for a chi-square test applied to a cross-tabulation with 4 rows and 3 columns is equal to: (Hints: df = (# of rows - 1) * ( # of columns - 1))
6
Before moving away to college, Lisa is warned about the high cost of parking tickets close to campus. To determine the validity of the warning, Lisa asks 10 other students at registration how long they have been a student (X) and how much they paid last year in parking tickets (Y). The data and analysis are as follows: What is the number of degrees of freedom appropriate for the t-test?
8
Which of the following is not a requirement for using the chi-square statistic?
A comparison of only one group is necessary
If fear of crime initially decreases with age, but then after age 40 reverses itself, this correlation would be an example of:
A curvilinear relationship
Which statement is NOT true of correlation coefficients?
Correlations provide statements of causation.
A criminologist wonders if there is a relationship between how often people watch television news (X) and their fear of crime (Y). The researcher conducts a survey asking how many days per week do you watch the local television news and how afraid are you to walk in your own neighborhood after dark. The degree of fear is measured on a scale from 0 to 10, where 0 is "none at all" and 10 is "completely afraid." Use the following information to answer the questions. What is your decision for a two-tailed test for this problem?
Fail to reject the Null Hypothesis
A chi-square tests depends the interval level of measurement.
False
A correlation coefficient is considered a measure of variation.
False
Correlation coefficients do NOT indicate the strength of a relationship.
False
In a chi-square test of significance, the dependent variable is measured at the interval level.
False
The degrees of freedom for a chi-square test depend on the sample size.
False
The following six students were questioned regarding their attitudes toward the legalization of prostitution (X) and their attitudes toward the legalization of marijuana (Y). Use the following data and analysis to answer the question. What is the two-tailed decision for this problem?
NOT Fail to Reject the Null Hypothesis
The following six students were questioned regarding their attitudes toward the legalization of prostitution (X) and their attitudes toward the legalization of marijuana (Y). Use the following data and analysis to answer the question. The Pearson correlation coefficient for this data is
NOT a moderate positive correlation
A criminologist wonders if there is a relationship between how often people watch television news (X) and their fear of crime (Y). The researcher conducts a survey asking how many days per week do you watch the local television news and how afraid are you to walk in your own neighborhood after dark. The degree of fear is measured on a scale from 0 to 10, where 0 is "none at all" and 10 is "completely afraid." Use the following information to answer the questions. The Pearson correlation coefficient for this data is
NOT a strong positive correlation
In statistics, r is called:
Pearson's correlation coefficient
Before moving away to college, Lisa is warned about the high cost of parking tickets close to campus. To determine the validity of the warning, Lisa asks 10 other students at registration how long they have been a student (X) and how much they paid last year in parking tickets (Y). The data and analysis are as follows: What is the decision for a two-tailed test?
Reject the Null Hypothesis
The increase or decrease in Y expected with each unit change in X is known as:
The regression coefficient or slope, b
Which of the following is FALSE of nonparametric tests?
They require a normal distribution.
A chi-square test is a nonparametric test of significance.
True
A correlation coefficient of -.60 is a stronger correlation than a correlation coefficient of +.55
True
A weak correlation coefficient could result from a curvilinear relationship.
True
A strong correlation between variables X and Y implies:
X is a good predictor of Y.
The mathematical equation for a regression line is typically written:
Y = a + bx + e
The direction of a correlation is indicated by:
a - its sign (+ or - ).
The set of frequencies obtained in an actual frequency distribution are the:
a - observed frequencies.
A researcher takes a sample and wants to compare the results to the population from which it was drawn. The independent variable is "gender" and the dependent variable is a yes/no response to whether they favor the abortion. What test would the researcher use to see if results are significant?
a Chi-square test
A researcher takes a sample and wants to compare the results to the population from which it was drawn. The independent variable is "gender" and the dependent variable is a yes/no response to whether they support the death penalty. What test would the researcher use to see if results are significant?
a Chi-square test
As years of education increase, the likelihood of domestic violence decreases, is an example of:
a negative relationship
Parametric tests require:
a normal distribution.
Nonparametric tests are useful when:
all of the above
The correlation coefficient:
all of the above
Which of the following is NOT a requirement for regression analysis?
all of the above are requirements
Which of the following is required in order to compute a Pearson's correlation coefficient?
all of the provided answers
The frequencies proposed under the terms of the null hypothesis are the:
b - expected frequencies.
The strength of the correlation is indicated by:
b - its numerical value.
Correlation can vary with respect to:
b and c
Small expected frequencies cause the value of the chi-square statistic to:
become much larger.
As the observed frequencies get closer to the expected frequencies, the value of the chi-square statistic:
becomes smaller.
The coefficient of determination is:
both b and c
The square of Pearson's r () is known as the:
both b and c
1-r^2 is known as the:
coefficient of nondetermination.
The variable being predicted in a regression analysis is called the:
dependent variable
Regression analysis creates a mathematical function which predicts the value of the __________ on the basis of the __________.
dependent variable; independent variable
The correlation coefficient can vary with respect to:
direction and strength. idk
A correlation coefficient typically includes variables measured at the ordinal level.
false
Correlation coefficients do not indicate the strength of a relationship.
false
Pearson's Correlation Coefficient must have two ordinal variables.
false
Pearson's correlation coefficient assesses the strength and direction of curvilinear relationships.
false
Regression equations can only have one independent variable.
false
r^2 is the coefficient of nondetermination.
fe
A positive correlation between variables X and Y implies:
high scores on X are associated with high scores on Y.
A negative correlation between variables X and Y implies:
high scores on X are associated with low scores on Y.
The strength of a correlation is indicated by:
its numerical value.
The direction of the correlation is indicated by:
its sign (+ or - ).
In a one-way chi-square, the appropriate number of degrees of freedom is:
k-1
An important first step in assessing the relationship of two interval level variables is to:
look at a scatter plot.
If the variable Crime increases as the variable Police Presence decreases, the correlation is said to be:
negative
Which of the following is NOT a requirement of the median test?
nominal data
If a Pearson's r for A and B is calculated to be +.95, we can confidently report that:
none of the provided answers
Nonparametric tests REQUIRE:
none of the provided answers
In regression analysis:
one variable is believed to be influenced by the other.
The __________ is a very useful statistic for finding spurious relationships.
partial correlation coefficient
If the variable Self-Control increases as the variable Education increases, the correlation is said to be:
positive
The formula for Chi-Square x^2 is
sigma (Fo-Fe)^2/Fe
Which of the following is not a component of the regression equation?
standard deviation
When the points in a scatter plot cluster closely around the regression line, the correlation can be said to be:
strong
In a regression equation, a refers to:
the Y-intercept (point where the regression line crosses the Y-axis when X = 0).
A chi-square test of significance is essentially concerned with:
the distinction between expected and observed frequencies.
The difference between the observed points and the regression line points is equal to:
the error term.
Expected frequencies represent:
the frequencies one would expect if the null hypothesis were true.
The median test determines:
the likelihood that the samples were drawn from populations with equal medians.
The coefficient of non-determination explains:
the proportion of variance in Y that is NOT determined or explained by X.
The coefficient of determination explains:
the proportion of variance in Y that is determined or explained by X
If a correlation between variables A and B is found to be equal to -1.16:
there has been a miscalculation.
A chi-square test should be used with caution when:
there is an expected frequency < 5.
A correlation coefficient requires both variables to be measured at the interval level.
true
The closer the correlation coefficient is to 0 the weaker the correlation.
true
X is generally considered to be the independent variable in a regression analysis.
true
If a chi-square expected frequency is less than 10 but greater than 5, one should:
use Yates' correction.
A strong curvilinear relationship between two variables might yield a Pearson's r that is:
weak or close to 0.
If the variable Crime Attractiveness increases as the variable Age remains constant, the correlation is said to be:
zero
If variable X increases as variable Y remains constant, the correlation is said to be:
zero
The correlation between the midterm and the final grades is:
zero
The correlation between two variables that are totally unrelated would be:
zero
A criminologist wonders if there is a relationship between how often people watch television news (X) and their fear of crime (Y). The researcher conducts a survey asking how many days per week do you watch the local television news and how afraid are you to walk in your own neighborhood after dark. The degree of fear is measured on a scale from 0 to 10, where 0 is "none at all" and 10 is "completely afraid." Use the following information to answer the questions. What is the critical t-value for this problem?
±2.306
Before moving away to college, Lisa is warned about the high cost of parking tickets close to campus. To determine the validity of the warning, Lisa asks 10 other students at registration how long they have been a student (X) and how much they paid last year in parking tickets (Y). The data and analysis are as follows: What is the critical t-value for this problem?
±2.306
The following six students were questioned regarding their attitudes toward the legalization of prostitution (X) and their attitudes toward the legalization of marijuana (Y). Use the following data and analysis to answer the question. What is the critical t-value for this problem?
±2.776