Download Chapter 11 practice test Provide an appropriate response. 1) The

Chapter 11 practice test
Provide an appropriate response.
1) The two-way table summarizes data from a survey at a small liberal arts college:
New Hires
Tenure Adjunct Total
Men
Women
Total
19
25
44
25
17
42
1)
44
42
86
What is the probability (rounded to two decimal places) that a randomly selected new hire is a
tenure-track woman?
A) 0.29
B) 0.20
C) 0.25
D) 0.60
E) 0.49
2) The two-way table summarizes data from a survey at a small liberal arts college:
New Hires
Tenure Adjunct Total
Men
Women
Total
22
19
41
20
25
45
2)
42
44
86
What is the probability (rounded to three decimal places) that a tenure-track new hire is female?
A) 0.463
B) 0.221
C) 0.477
D) 0.556
E) 0.432
Group the bivariate data into a contingency table.
3) The table below provides data on sex, political party affiliation, and income bracket for a sample of
people questioned during a poll. Group the bivariate data for the two variables "sex" and "income
bracket" into a contingency table.
Sex
M
F
F
M
F
M
F
M
M
F
M
F
F
M
M
F
M
F
M
F
M
M
Political Party Income Bracket
Rep
Dem
Dem
Dem
Other
Rep
Rep
Rep
Dem
Rep
Dem
Rep
Dem
Dem
Rep
Dem
Rep
Other
Other
Dem
Dem
Rep
High
Middle
Middle
Low
Middle
Low
High
High
High
Low
High
Middle
Middle
Middle
Low
High
Low
High
Middle
Low
Middle
Low
1
3)
F
Dem
Middle
A)
B)
C)
D)
E) None of the above.
Provide an appropriate response.
4) During a poll, 146 people were randomly selected and asked their political
party affiliation. The contingency table below shows the results cross
classified by political party affiliation and sex.
Find the conditional distribution of political party affiliation for women.
A) Democrats: 32.4%; Republicans: 37.8%; Others: 29.7%
B) Democrats: 47.8%; Republicans: 44.0%; Others: 56.0.%
C) Democrats: 16.4%; Republicans: 19.2%; Others: 15.1%
D) Democrats: 31.5%; Republicans: 34.2%; Others: 34.2%
E) Democrats: 52.2%; Republicans: 56%; Others: 44%
2
4)
Use contingency table to estimate expected cell count.
5) The contingency table below shows the results of a random sample of 200 state representatives that
was conducted to see whether their opinions on a bill are related to their party affiliation.
Assuming the row and column classification are independent, find an estimate for the expected cell
count of row 2, column 2. Round your answer to tenths.
Opinion
Party
Approve Disapprove No Opinion
Republican
42
20
14
Democrat
50
24
18
Independent
10
16
6
A) 24
B) 22.8
C) 22.2
D) 27.6
E) 46.92
Use chi-square table.
6) Use the appropriate table to find the following chi-square value: 2 = 0.025 for df = 2.
A) 9.35
B) 7.38
C) 5.99
D) 2.77
E) 5.02
7) Use the appropriate table to find the following probability: P( 2 13.28) for df = 4.
A) 0.005
B) 0.010
C) 0.100
D) 0.990
5)
E) 0.02
Use the contingency table.
8) The contingency table below shows the results of a random sample of 200 state representatives that
was conducted to see whether their opinions on a bill are related to their party affiliation. Use =
0.05.
6)
7)
8)
Opinion
Party
Approve Disapprove No Opinion
Republican
42
20
14
Democrat
50
24
18
Independent
10
16
6
Find the rejection region to test the claim of independence.
A) 2 > 16.92
B) 2 > 9.49
C) 2 > 7.81
D) 2 > 7.78
E) 2 > 11.14
9) The contingency table below shows the results of a random sample of 200 state representatives that
was conducted to see whether their opinions on a bill are related to their party affiliation.
Opinion
Party
Approve Disapprove No Opinion
Republican
42
20
14
Democrat
50
24
18
Independent
10
16
6
Find the chi-square test statistic, 2 , to test the claim of independence.
A) 9.483
B) 11.765
C) 4.41
D) 8.030
3
E) 7.662
9)
Select the most appropriate answer.
10) The chi-squared test statistic for testing the independence of two categorical variables is
A)
all cells
B)
all cells
C)
all cells
D)
10)
(observed cell count - expected cell count)
observed cell count
(observed cell count - expected cell count)
expected cell count
(observed cell count - expected cell count)2
expected cell count
(observed cell count - expected cell count)2
observed cell count
all cells
E) none of the above.
Provide an appropriate response.
11) In a 2 test of independence, the null hypothesis is that
A) there is an association.
B) the random variables are dependent.
C) each sample has equal frequency.
D) there is not an association.
E) each element of each set has the same probablity of occurrences.
12) As the number of degrees of freedom increases, the 2 distribution
A) becomes more symmetric.
B) becomes less symmetric.
C) becomes exponential.
D) becomes less robust.
E) does not change shape as the degrees of freedom change.
Select the most appropriate answer.
13) Whenever a statistic has a standard normal distribution, the square of that statistic has a
chi-squared distribution with
A) df = (r - 1) × (c - 1).
B) df = (n -1)2 .
C) df = n -1.
D) df = n -2.
E) df = 1.
14) The minimum possible value of the chi-squared test statistic, X2 = 0, would occur if the observed
count is
A) less than the expected count in each cell.
B) equal to the expected count in each cell.
C) more than the expected count in each cell.
D) less than the expected count as often as it is more than the expected count.
E) .equal to the expected count overall.
4
11)
12)
13)
14)
15) The degrees of freedom in a chi-squared test of independence of two categorical variables which
produce a 3 × 8 contingency table are
A) 20.
B) 14.
C) 24.
D) 23.
E) 22.
State the null hypothesis to test for independence.
16) Responses to a survey question are broken down according to employment status and the sample
results are given below. At the 0.10 significance level, test the claim that response and employment
status are independent.
Yes No Undecided
Employed 30 15
5
Unemployed 20 25
10
A) H0 : Employment status and response are independent.
15)
16)
B) Ha: Employment status and response are dependent.
C) Ha: Employment status and response are independent.
D) H0 : Employment status and response are dependent.
17) The table below shows the age and favorite type of music of 668 randomly selected people.
Rock Pop Classical
15-25
50 85
73
25-35
68 91
60
35-45
90 74
77
Use a 5 percent level of significance to test the null hypothesis that age and preferred music type
are independent.
A) H0 : Age and preferred music type are independent.
17)
B) H0 : Age and preferred music type are dependent.
C) Ha: Age and preferred music type are dependent.
D) Ha: Age and preferred music type are independent.
Calculate 2 from contingency table.
18) Tests for adverse reactions to a new drug yielded the results given in the table. At the 0.05
significance level, test the claim that the treatment (drug or placebo) is independent of the reaction
(whether or not headaches were experienced).
Drug Placebo
Headaches
11
7
No headaches
73
91
H0 : Treatment and reaction are independent.
Ha: Treatment and reaction are dependent.
Find 2.
A) 4.605
B) 7.815
C) 1.798
5
D) 3.841
E) 5.942
18)
19) Responses to a survey question are broken down according to gender and the sample results are
given below. At the 0.05 significance level, test the claim that response and gender are independent.
Yes No Undecided
Male 25 50
15
Female 20 30
10
19)
H0 : Gender and response are independent.
Ha: Gender and response are dependent.
Find 2.
A) 3.841
B) 5.991
C) 0.579
D) 2.706
E) 6.502
Use the 2 test to test the claim that in the given contingency table, the row variable and the column variable are
independent.
20) Tests for adverse reactions to a new drug yielded the results given in the table. At the 0.05
20)
significance level, test the claim that the treatment (drug or placebo) is independent of the reaction
(whether or not headaches were experienced).
Drug Placebo
Headaches
11
7
No headaches
73
91
H0 : Treatment and reaction are independent.
Ha: Treatment and reaction are dependent.
Test statistic: 2 = 1.798.
State your conclusion about H0.
A) No conclusion can be made.
B) Reject Ha.
C) Do not reject Ha .
D) Reject H0.
E) Do not reject H0 .
21) The table below shows the age and favorite type of music of 668 randomly selected people.
Rock Pop Classical
15-25
50 85
73
25-35
68 91
60
35-45
90 74
77
5 percent level of significance is to be used to test the null hypothesis that age and preferred music
type are independent.
H0 : Age and preferred music type are independent.
Ha: Age and preferred music type are dependent.
Test statistics 2 = 12.954
State your conclusion about H0.
A) Accept Ha .
B) Reject H0.
C) Fail to reject H0.
D) Reject Ha.
E) No conclusion can be made.
6
21)
Provide an appropriate response.
22) In a chi-square test of homogeneity of proportion we test the claim that
A) the proportion of individuals with a given characteristic doesn't change over time.
B) across a single sample the proportion of individual with the same characteristic is the same as
the population.
C) different populations have the same proportions of individuals with the same characteristics.
D) different populations have equal means.
E) the proportion of a population having a given characteristic is based on the homogeneity of
the population.
23) At a high school debate tournament, half of the teams were asked to wear suits and ties and the rest
were asked to wear jeans and t-shirts. The results are given in the table below. Test the hypothesis
at the 0.05 level that the proportion of wins is the same for teams wearing suits as for teams
wearing jeans.
Win Loss
Suit 22
28
T-shirt 28
22
H0 : The proportion of wins is the same for teams wearing suits as for teams wearing jeans.
22)
23)
Ha: The proportions are different.
Test statistic: 2 = 1.440. Critical value: 2 = 3.841.
State your conclusion about null hypothesis.
A) No conclusion can be made.
B) Reject H0.
C) Reject Ha.
D) Fail to reject Ha.
E) Fail to reject H0.
24) A researcher wishes to test whether the proportion of college students who smoke is the same in
four different colleges. She randomly selects 100 students from each college and records the
number that smoke. The results are shown below.
College A College B College C College D
Smoke
17
26
11
34
Don't smoke
83
74
89
66
Use a 0.01 significance level to test the claim that the proportion of students smoking is the same at
all four colleges.
H0 : The proportion of students smoking is the same at all four colleges.
Ha: The proportions are different.
Test statistic: 2 = 17.832. Critical value: 2 = 11.345.
State your conclusion about the null hypothesis.
A) No conclusion can be made.
B) Reject H0.
C) Fail to reject H1.
D) Reject H1.
E) Fail to reject H0.
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24)
Answer Key
Testname: CH11PRAC
1) A
2) A
3) D
4) A
5) D
6) B
7) B
8) B
9) D
10) C
11) D
12) A
13) E
14) B
15) B
16) A
17) A
18) C
19) C
20) E
21) B
22) C
23) E
24) B
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