Question

1. You have a dataset from a random sample of U.S. adults and are analyzing two variables measured as follows:Sex (0=male; 1=female) and Felony criminal record (0=no; 1=yes). Which statistic is most appropriate for describing the strength of the relationship between these two variables?

Chi-square

Phi-coefficient

Goodman and Kruskal's gamma

Yule's Q

None of the above

2. A hypothesis test for the difference between two independent sample means assumes ____________.

we have two samples that are independently selected

we have two samples that are each randomly selected

there is a known probability of any element being selected into a sample

the selection of an element into one sample has no effect on the selection of any element into the other sample

This test makes all of the above assumptions

3. Which of the following statements best describes the sampling distribution of sample mean differences?

It is the true value of μ1 – μ2, or the difference in population means

It is the difference between the observed sample means of two samples

It is the normally distributed difference in observed values of X across two samples

It is the theoretical distribution of the difference between an infinite number of sample means

None of the above statements accurately describes this concept

4. After collecting data on age and number of speeding tickets, the researcher found that older people are less likely to have speeding tickets. What type of correlation is this between the two variables age and number of speeding tickets?

positive

null

negative

scattered

none of the above

5. A study found that high school students who are more involved in structured after-school activities are also less likely to use drugs. Which of the following correlation coefficients most likely reflects this relationship between the two variables involvement and drug use?

r = 1.00

r = -0.40

r = 0.30

r = 0.00

none of the above

Answer 1

1. Phi-coefficient because the phi coefficient is a measure of association for two binary variables.

2. This test makes all of the above assumptions

3. It is the theoretical distribution of the difference between an infinite number of sample means

4. negative because as the age increases, the number of speeding ticket decreases.

5. r = -0.40 because there is a negative correlation between the two variables involvement and drug use.

As the involvement increase, the drug use decrease.