davenport stat500 week 6 quiz ch 10
by ella | Feb 26, 2025 | Statistics
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Given the linear correlation coefficient r and
the sample size n, determine the critical values of r. Use your finding to
state whether or not the given r represents a significant linear correlation.
Use a significance level of 0.05.
r = -0.844, n = 5
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Question 2
5 out of 5 points
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A set of data consists of the number of years
that applicants for foreign service jobs have studied German and the grades
they received on a proficiency test. The following regression equation is
obtained: y = 31.6 + 10.9x, where x represents the number of years of study
and y represents the grade on the test. What does the slope of the regression
line represent in terms of a grade on the test?
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Question 3
10 out of 10 points
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Find the value of the linear correlation coefficient r.
The paired data below consist of the test scores of 6 randomly selected
students and the number of hours they studied for the test.
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Hours
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5
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10
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4
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6
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10
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9
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Score
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64
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86
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69
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86
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59
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87
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Question 4
0 out of 5 points
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Select the appropriate conclusion based on the
following result:
There is no significant linear correlation between scores on a math test and
scores on a verbal test.
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Question 5
5 out of 5 points
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Use the given data to find the best predicted
value of the response variable.
Eight pairs of data yield r = 0.708 and the regression equation y = 55.8 +
2.79x. Also, mean y = 71.125. What is the best predicted value of y for x =
5.7?
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Question 6
5 out of 5 points
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Which
of the following is NOT one of the most common sources or errors made in
interpreting correlation results?
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Question 7
5 out of 5 points
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Which of the following describes the coefficient
of determination?
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Question 8
5 out of 5 points
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Use the given information to find the coefficient
of determination.
A regression equation is obtained for a collection of paired data. It is
found that the total variation is 29.045, and the UNexplained variation is
13.833. Find the coefficient of determination.(Hint: You must first find the
explained variation.)
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Question 9
5 out of 5 points
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Which of the following is a property of the
linear correlation coefficient r?
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Question 10
0 out of 5 points
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Use the computer display to answer the question.
A collection of paired data consists of the number of years that students
have studied Spanish and their scores on a Spanish language proficiency test.
A computer program was used to obtain the least squares linear regression
line and the computer output is shown below. Along with the paired sample
data, the program was also given an x value of 2 (years of study) to be used
for predicting test scores.
The regression equation is
score = 31.55 + 10.90(years).
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Pred
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Coeff
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Std
Dev
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T
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P
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Constant
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31.55
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3.360
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4.96
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0.000
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Years
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10.90
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1.744
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6.25
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0.000
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S =
5.651
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R Sq=
83.0%
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R Sq
(Adj) = 82.7%
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Predicted
Values
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Fit
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Std
Dev Fit
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95%
CI
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95%
PI
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53.35
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3.168
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(42.72,
63.98)
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(31.61,
75.09)
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For a person who studies for 2 years, obtain the
95% prediction interval and write a statement interpreting the interval.
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Question 11
5 out of 5 points
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Which of the following research hypotheses would be answered using a
multiple regression?
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