Deck 12: Infectious Conditions

Question 1

When performing a hypothesis test to compare two or more population proportions, the null hypothesis is always that not all population proportions are equal.

Answer 1

False

Question 2

The chi- square test for independence is used to decide if observed frequencies follow a known probability distribution.

Answer 2

False

Question 3

Nationwide Insurance would like to perform a chi- square test to investigate whether a difference exists in the proportion of male and female teenagers who text while they drive. A random sample of 80 male teenagers found that 50 indicated they texted while driving. A random sample of 120 female teenagers found that 65 indicated they texted while driving. The chi- square critical value using α = 0.5 is ______ .

A)5.991
B)2.706
C)3.841
D)7.815

Answer 3

3.841

Question 4

The _____ frequencies refer to the frequencies that are most likely to occur if the null hypothesis is true when performing a hypothesis test comparing two or more population proportions.

A)observed
B)cumulative
C)expected
D)relative

Question 5

Nationwide Insurance would like to perform a chi- square test to investigate whether a difference exists in the proportion of male and female teenagers who text while they drive. A random sample of 80 male teenagers found that 50 indicated they texted while driving. A random sample of 120 female teenagers found that 65 indicated they texted while driving. The degrees of freedom for the chi- square critical value is ______.

A)3
B)1
C)4
D)2

Question 6

When testing for a normal distribution with the chi- square goodness- of- fit test with a sample size of 240 observations, the number of intervals needed to satisfy the minimum number of expected frequencies is ______ .

A)5
B)6
C)4
D)The sample size is too small to perform the chi- square goodness- of- fit test.

Question 7

When testing for a normal distribution with the chi- square goodness- of- fit test with a sample size of 50 observations, the number of intervals needed to satisfy the minimum number of expected frequencies is _____-_ .

A)The sample size is too small to perform the chi- square goodness- of- fit test.
B)4
C)5
D)6

Question 8

Nationwide Insurance would like to perform a chi- square test to investigate whether a difference exists in the proportion of male and female teenagers who text while they drive. A random sample of 80 male teenagers found that 50 indicated they texted while driving. A random sample of 120 female teenagers found that 65 indicated they texted while driving. The expected frequency of female teenagers who text is ______.

A)51
B)55
C)65
D)69

Question 9

The rejection region for the chi- square test to compare two or more population proportions lies on the right tail of the chi- square distribution.

Question 10

When performing a hypothesis test to compare two or more population proportions, the test statistic follows the ______.

A)chi- square distribution
B)F- distribution
C)Student's t- distribution
D)normal distribution

Question 11

The ______ frequencies refer to the sample data collected from a population of interest when performing a hypothesis test comparing two or more population proportions.

A)observed
B)expected
C)cumulative
D)relative

Question 12

The chi- square test requires that each expected frequency be equal to or greater than _____.

A)30
B)10
C)20
D)5

Question 13

When using the chi- square hypothesis test and the observed frequencies are relatively close to the expected frequencies, which one of the following statements is true?

A)The scenario will result in a smaller chi- square statistic, which increases the likelihood that there is support for the null hypothesis.
B)The scenario will result in a larger chi- square statistic, which increases the likelihood that there is support for the alternative hypothesis.
C)The scenario will result in a larger chi- square statistic, which increases the likelihood that there is support for the null hypothesis.
D)The scenario will result in a smaller chi- square statistic, which increases the likelihood that there is support for the alternative hypothesis.

Question 14

Nationwide Insurance would like to perform a chi- square test to investigate whether a difference exists in the proportion of male and female teenagers who text while they drive. A random sample of 80 male teenagers found that 50 indicated they texted while driving. A random sample of 120 female teenagers found that 65 indicated they texted while driving. Using α = 0.5, the conclusion for this chi- square test would be that because the test statistic is

A)less than the critical value, we can reject the null hypothesis and conclude that there is a difference in the proportion of male and female teenagers who text while they drive.
B)more than the critical value, we cannot reject the null hypothesis and conclude that there is no difference in the proportion of male and female teenagers who text while they drive.
C)less than the critical value, we cannot reject the null hypothesis and cannot conclude that there is a difference in the proportion of male and female teenagers who text while they drive.
D)more than the critical value, we can reject the null hypothesis and conclude that there is a difference in the proportion of male and female teenagers who text while they drive.

Question 15

Nationwide Insurance would like to perform a chi- square test to investigate whether a difference exists in the proportion of male and female teenagers who text while they drive. A random sample of 80 male teenagers found that 50 indicated they texted while driving. A random sample of 120 female teenagers found that 65 indicated they texted while driving. The expected frequency of male teenagers who text is _______.

A)34
B)50
C)30
D)46

Question 16

When testing for a normal distribution with the chi- square goodness- of- fit test with a sample size of 100 observations, the number of intervals needed to satisfy the minimum number of expected frequencies is _______ .

A)5
B)The sample size is too small to perform the chi- square goodness- of- fit test.
C)4
D)6

Question 17

The airline industry defines no- shows as passengers who have purchased a ticket but fail to arrive at the gate on time for departure. Southwest Airlines operates many flights from Philadelphia to Dallas and experienced the following no- show probability distribution last year.
$$\begin{array} { l | l | l | l | l | l | l | l } \text { No-shows } & 0 & 1 & 2 & 3 & 4 & 5 & 6 \\\hline \text { Probability } & 6 \% & 12 \% & 22 \% & 28 \% & 17 \% & 11 \% & 4 \%\end{array}$$
The following data represent the number of no-show has changed between last year on flights between these cities using ?=0.05. The degrees of freedom for the critical value is _____

A)4
B)6
C)5
D)3

Question 18

When testing for a normal distribution with the chi- square goodness- of- fit test with a sample size of 30 observations, the number of intervals needed to satisfy the minimum number of expected frequencies is ________ .

A)The sample size is too small to perform the chi- square goodness- of- fit test.
B)4
C)6
D)5

Question 19

Nationwide Insurance would like to perform a chi- square test to investigate whether a difference exists in the proportion of male and female teenagers who text while they drive. A random sample of 80 male teenagers found that 50 indicated they texted while driving. A random sample of 120 female teenagers found that 65 indicated they texted while driving. The chi- square test statistic for this sample is ______.

A)4.05
B)1.36
C)4.22
D)2.98

Question 20

For a chi- square test of independence, the expected frequencies are calculated under the assumption that the null hypothesis is true.

Question 21

The chi- square goodness- of- fit test has no minimum requirement for the number of observed frequencies in each category.

Question 22

The chi- square test of independence does not allow us to state that one variable causes a change in another variable when the null hypothesis is rejected.

Question 23

The null hypothesis for a chi- square goodness- of- fit test always states that the stated distribution is followed.

Question 24

For a chi- square test of independence, the expected frequencies are permitted to be less than 5.

Question 25

The null hypothesis for a chi- square test of independence always states that the two variables are not independent of one another.

Question 26

When performing a hypothesis test to compare two or more population proportions, the observed frequencies must always be integer values.

Question 27

The chi- square goodness- of- fit test is used to determine if two categorical variables are independent of one another.

Question 28

When the chi- square test statistic is greater than the chi- square critical value when comparing two or more population proportions, we fail to reject the null hypothesis.

Question 29

When performing a hypothesis test to compare two or more population proportions, the expected frequencies must always be integer values.

Question 30

The shape of the chi- square distribution is left- skewed.

Question 31

Two variables are dependent if changes in the levels of one variable do not affect the levels of the other variable.

Question 32

When we reject the null hypothesis for a chi- square test of independence, we are concluding that there is no relationship between the two variables.