Question

A psychologist studying addiction tests whether cravings for cocaine and relapse are independent. The following table lists the observed frequencies in the small sample of people who use drugs.

Obs. Freq. Relapse

Yes No

Cravings Yes 21 12 33

No 6 15 21

27 27 N = 54

(a) Conduct a chi-square test for independence at a 0.05 level of significance. (Round your answer to two decimal places.)

Decide whether to retain or reject the null hypothesis.

(b) Compute effect size using ϕ and Cramer's V. Hint: Both should give the same estimate of effect size. (If necessary, round your intermediate steps to two or more decimal places. Round your answers to two decimal places.)

ϕ =

V =

Answer #1

a)

Applying chi square test of independence: |

Expected |
E_{i}=row total*column
total/grand total |
Yes | No | Total |

Yes | 16.5000 | 16.5000 | 33 | |

No | 10.5000 | 10.5000 | 21 | |

total | 27 | 27 | 54 | |

chi square χ^{2} |
=(O_{i}-E_{i})^{2}/E_{i} |
Yes | No | Total |

Yes | 1.227 | 1.227 | 2.4545 | |

No | 1.929 | 1.929 | 3.8571 | |

total | 3.1558 | 3.1558 | 6.3117 | |

test
statistic X^{2} = |
6.3117 | |||

p value = | 0.0120 |

from above: test statistic **=6.31**

since p value < 0.05 , we reject null hypothesis

b)

Phi cpefficieint =φ=√(X^{2}/n)= |
0.34 |

Cramer V=φ_{c}=√(X^{2}/(n*(k-1)))= |
0.34 |

A psychologist studying addiction tests whether cravings for
cocaine and relapse are independent. The following table lists the
observed frequencies in the small sample of people who use
drugs.
Obs. Freq.
Relapse
Yes
No
Cravings
Yes
21
11
32
No
8
17
25
29
28
N = 57
(a) Conduct a chi-square test for independence at a 0.05 level
of significance. (Round your answer to two decimal places.)
(the correct symbols won't transfer but it is as follows)...

A psychologist studying addiction tests whether cravings for
cocaine and relapse are independent. The following table lists the
observed frequencies in the small sample of people who use
drugs.
Obs. Freq.
Relapse
Cravings Yes No
Yes 20 13 33
No 7 17 24
TOTAL 27 30 N=57
(a) Conduct a chi-square test for independence at a 0.05 level
of significance. (Round your answer to two decimal places.)
x^2{obt}=
(b) Compute effect size using ϕ and Cramer's V. Hint: Both
should...

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The following table shows the observed frequencies for this
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Medium
High
Exam
Pass
21
18
9
48
Fail
9
7
11
27
30
25
20
N = 75
(a) Conduct a chi-square test for independence at a 0.05 level
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=
Decide whether to retain or...

A professor tests whether the loudness of noise during an exam
(low, medium, and high) is independent of test grades (pass, fail).
The following table shows the observed frequencies for this
test.
Noise Level
Low
Medium
High
Test
Pass
19
16
8
43
Fail
8
6
10
24
27
22
18
N = 67
(a) Conduct a chi-square test for independence at a 0.05 level
of significance. (Round your answer to two decimal places.)
=
Decide whether to retain or...

A professor tests whether the loudness of noise during an exam
(low, medium, and high) is independent of exam grades (pass, fail).
The following table shows the observed frequencies for this test.
Noise Level Low Medium High Exam Pass 21 16 8 45 Fail 8 5 10 23 29
21 18 N = 68 (a) Conduct a chi-square test for independence at a
0.05 level of significance. (Round your answer to two decimal
places.) $ \chi_{obt}^2 $ = Correct: Your...

A professor tests whether the loudness of noise during an exam
(low, medium, and high) is independent of exam grades (pass, fail).
The following table shows the observed frequencies for this test.
Noise Level Low Medium High Exam Pass 19 16 9 44 Fail 9 7 11 27 28
23 20 N = 71 (a) Conduct a chi-square test for independence at a
0.05 level of significance. (Round your answer to two decimal
places.) $ \chi_{obt}^2 $ = Decide whether...

Treatment for Cocaine Addiction
Cocaine addiction is very hard to break. Even among addicts trying
hard to break the addiction, relapse is common. (A relapse is when
a person trying to break out of the addiction fails and uses
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A professor tests whether the loudness of noise during an exam
(low, medium, and high) is independent of exam grades (pass,
fail).
The following table shows the observed frequencies for this
test.
Noise Level
Low Medium High
Exam Pass 19 16 9 44
Fail 9 6 10 25
28 22 19 N = 69
(a) Conduct a chi-square test for independence at a 0.05 level
of significance. (Round your answer to two decimal place)
Decide whether to retain or reject...

A professor tests whether the loudness of noise during an exam
(low, medium, and high) is independent of exam grades (pass, fail).
The following table shows the observed frequencies for this test.
Noise Level Low Medium High Exam Pass 19 16 9 44 Fail 9 6 10 25 28
22 19 N = 69 (a) Conduct a chi-square test for independence at a
0.05 level of significance. (Round your answer to two decimal
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A professor tests whether the loudness of noise during a test
(low, medium, and high) is independent of test grades (pass, fail).
The following table shows the observed frequencies for this
test.
Noise Level
Low
Medium
High
Test
Pass
20
16
8
44
Fail
8
6
11
25
28
22
19
N = 69
(a) Conduct a chi-square test for independence at a 0.05 level
of significance. (Round your answer to two decimal places.)
X2obt =
(b) Compute effect size...

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