quantitative methods exam 1

a pearson correlation describes the relationship between two: a. equal interval numeric variables b. scatterplots c. standard deviations d. horizontal axes

a

a researcher notes that the correlation in the sample she studied is so large that if there were not a correlation among people in the general population, then there is less than a 5% chance of obtaining her correlation. her correlation is thus: a. statistically significant b. statistically insignificant c. nonlinear d. curvilinear

a

in a histogram, the horizontal dimension displays a: a. range of possible values the variable can have b. percentile score for each individual c. mean score d. frequency

a

the different between scores of 3 and 4 is approximately the same as the difference between scores of 15 and 16, the type of variable is known as: a. equal interval b. differential c. non differential d. rank-order

a

unless there are _____behavioral and social scientists generally use the mean as the measure of the representative value of a group of scores. a. outliers b. histograms c. z scores d. two modes

a

a researcher discovers that if people eat a certain fruit before a test, the more fruit eaten, the better they do on a test. beyond a certain point however the more fruit eaten the worse people do on the test. the relation between amount of fruit eaten and how well people do on the test is an example of: a. a positive linear correlation b. a curvilinear correlation c. a negative linear correlation d. no correlation

b

an education researcher collects data on how many students are on scholarship at various local colleges. the researcher then makes a frequency table to summarize the data. the researcher is using a(n) a. measure of central tendency b. descriptive statistical method c. intuitive statistical method d. inferential statistical method

b

in a class of students in which everyone is exactly 24 years old, the variance would be: a. approximately 1 b. exactly 0 c. between 0 and 1 d. impossible to determine without more information

b

on the first exam in an introductory statistics class most students did very well and only a few did poorly. how would you describe the distribution of test scores? a. symmetrical b. skewed to the left c. having a floor effect d. skewed to the right

b

researchers say that a correlation is statistically significant if: a. the dots appear to form a straight line on the scatter diagram b. there is a small probability, such as less than 5% or 1% that you could have obtained a correlation this strong (or stronger) if in fact there had been no correlation in the population at large c. the correlation is .05 or greater (or below -.05 if negative) d. there is a large probability (.50 or larger), that this correlation is greater than that computed in standard tables of what is called the chi-square distribution

b

suppose you are making predictions about people's poetry ability based on scores on a general writing ability test. however you also happen to have information about their creativity scores when making your predictions. what is it called when you make a prediction using both pieces of information? a. ridge regression b. multiple regression c. bivariate regression d. proportion of variance

b

the word frequency in a frequency table refers to: a. cycles per seconds b. the number of scores at each value of a variable c. the times per unit change of each score d. the cumulative percentage for any given value

b

when is the correlation coefficient zero? a. it is never zero b. when there is no linear correlation c. when there is a perfect linear correlation d. when there is a perfect negative linear correlation

b

a student theorizes that performance on a statistics exam will be related to the number of hours she spent studying. she wants to generalize her funding to other courses she is taking as well. this student will be required to use ________ to test her theory. a. common sense b. reasoning by analogy c. inferential statistics d. intuition

c

all of the following are true statements about a z score except: a. it is the number of standard deviation the actual score is above or below the mean b. it is negative if the actual score falls below the mean c. it is negative if the actual score falls above the mean d. it is zero if the actual score falls at the mean

c

when a distribution is skewed to the right, it means that: a. there are more scores piled up at the high end of the range b. the scores are evenly distributed c. there are more scores piled up at the low end of the range d. there is a ceiling effect

c

when a distribution is skewed to the right: a. the median is greater than the mean b. the mean and the median are the same c. the mean is greater than the median d. the mean and the median are equal

c

which of the following represents he strongest linear correlation a. +.09 b. +.88 c. -.92 d. -.18

c

a researcher surveys job satisfaction among laborers and white collar workers. (job satisfaction is rated on a scale from 1=low satisfaction to 10=high satisfaction) results show that laborers have a mean job satisfaction score of 3 and a variance of 1; white collar workers have a mean job satisfaction rating of 7 and a variance of 10. which statement best describes what these numbers mean? a. white collar workers are less satisfied than laborers b. white collar workers and laborers are about equally satisfied c. laborers generally are less satisfied than white collar workers but laborers are just as likely to be highly satisfied as white collar workers are to be highly dissatisfied d. laborers are less satisfied than white collar workers and most laborers are more equally dissatisfied than white collar workers. there is more variation in the satisfaction of white collar workers

d

all of the following are examples of rank-order variables EXCEPT a. a students rank in his or her graduating class b. a tennis players standings compared to other athletes in the region c. a runners place finished in a race d. a students level of stress just before an exam is measured by heart rate

d

donald's z score on the statistics test was +1.25. this means that he scored a. slightly below the average b. just at the average c. a little less than one standard deviation below the mean d. more than one standard deviation above the mean

d

in a histogram, the vertical (up and down) dimension displays: a. possible values the variable can have b. intensity of the variable c. mean score d. frequency

d

the _____ is the usual way of describing the representative value for a nominal variable such as religious affiliation a. mean b. outlier c. median d. mode

d

the correlation coefficient squared is also called the: a. determinant of regression b. estimated error of correlation c. multiple regression constant d. proportion of variance accounted for

d

which of the following is not an advantage of z scores? a. you can compare scores from scales with different amounts of variation b. you can easily tell if a score is above or below the mean c. you can easily tell how far above or below the mean a score is d. you can easily tell the shape of the scores distribution

d

which of the following is not an example of a nominal variable a. hair color b. religious affiliation c. social security number d. score on an IQ test

d

while the mean provides a representative value of a group of scores, it does not tell about the _____ a. variability of the scores b. average of the scores c. spread of the scores around the mean d. both a and c

d