socy 2061 final q's

1.In a contingency table, two variables are said to be statistically independent when, within each category of one variable, the percentage distributions of the other variable are a. identical. b. unequal. c. descending. d. ascending

A

4. The obtained chi-square statistic summarizes the difference between __________ and __________ in a bivariate table. a. f o; f e b. y; Y c. µ1; µ2 d. t; Z

A

9. In the previous question, a "best-fitting" line drawn through the data points would most likely go a) straight across the page. b) straight down the page. c) from upper left to lower right. d) from lower left to upper right.

A

10. When we say that the correlation between Age and test Performance is significant, we mean a) there is an important relationship between Age and Performance. b) the true correlation between Age and Performance in the population is equal to 0. c) the true correlation between Age and Performance in the population is not equal to 0. d) getting older causes you to do poorly on tests.

B

The regression line always passes through the point a) 0, 0 b) , c) , 0 d) a, b

B

2. Which of the following is an assumption required by the chi-square test? (Choose all that apply) a. A normally distributed population b. Random sampling c. Standard deviation equal to 1.0 d. No extreme or outlying observations e. Observed frequencies are greater than or equal to 5 f. Expected frequencies are greater than or equal to 5

B,F

11. When I want to make a prediction but don't have the value of X on which to base that prediction, my best estimate is a) the value that I calculate with a regression equation. b) the smallest value of Y. c) the mean of Y. d) There is no good prediction.

C

6. A measure of association reflects the strength of a relationship and often the __________ of the relationship. a. determination b. stability c. direction d. definition

C

If we have a regression line predicting the amount of improvement in your performance as a function of the amount of tutoring you receive, an intercept of 12 would mean that a) you need to have 12 hours of tutoring to get an A. b) if you don't have any tutoring, the best you can do is a grade of 12. c) even without tutoring you will improve. d) tutoring helps

C

The notation is used instead of Y a) to indicate that the answer is only approximate. b) to indicate that we have an equation for a straight line. c) to indicate that the result is a prediction. d) because this is a mathematical equation.

C

. What is the null hypothesis for a chi-square test? a. There is an association between two variables in the population. b. There is an association between two variables in the sample. c. There is not an association between two variables in the population. d. There is not an association between two variables in the population.

D

5. Which of the following values could NOT be a chi-square statistic? a. 57.45 b. 57 c. .45 d. -57.4

D

7.Which pair of variables is least suited for analysis in a bivariate table or cross tabulation. number of years of schooling; annual income in dollars weight; height number of clicks using a computer mouse per hour; number of web pages visited per day none of the pairs is appropriate for bivariate table or cross tabulation

D

The following is a scatterplot of data that my students collected concerning the relationship between the cost of chocolate chip cookies and their rated quality. The correlation between the two variables is most likely to be: a) -.50 b) -.80 c) .80 d) .00

D

a. Directionality of a relationship can be determined when the independent variable is nominal.

F

a. In a bivariate table the expected frequency is computed (row total + column total)/(grand total).

F

a. The shape of the c2 distribution depends on the sample size.

F

A variable measured at the _INTERVAL-RATIO__ level of measurement has values that can be arranged from highest value to lowest with a known and consistent distance between the values.

INTERVAL-RATIO

A variable indicating job satisfaction is composed of categories ranked from "very dissatisfied" to "very satisfied." This variable is most likely measured at the ORDINAL level of measurement.

ORDINAL

. In a distribution of scores, the STANDARD DEVIATION represents the "average" distance of every score from the mean.

STANDARD DEVIATION

In a study analyzing the number of reported hate crimes across U.S. states, STATE is the unit of analysis.

STATE

a. A bivariate table or cross tabulation is used to arrange information on two variables simultaneously.

T

a. A row marginal is equivalent to a row subtotal.

T

a. The degrees of freedom for a bivariate table is given by (number of rows - 1)(number of columns - 1).

T

For measuring variability in a distribution, the standard deviation is usually preferred to the range because

b. it takes into account the deviation of every score in the distribution

Professor Davis is studying the effect of sleep on the likelihood of obesity. In her study, sleep is:

b. the independent variable Sleep Obesity (sleep is the cause of the effect [obesity])

3. Which of the following is an accurate statement about the mean?

c. The value of the mean is greatly affected by extreme scores.

If the mean of a distribution is higher than the mode and median, the distribution is probably:

c. positively skewed