Psy Exam 1

5. ______ are measured along a continuum at any place beyond the decimal point. A. Continuous data B. Discrete data C. Qualitative data D. Open-ended data

A. Continuous data

17. A researcher measures the number of trials it takes two samples of participants to master a new task. In both samples, SS = 240. Sample A consisted of 12 participants and Sample B consisted of 18 participants. Which sample is associated with a larger variance? A. Sample A B. Sample B C. Both samples have the same variance. D. There is not enough information to answer this question.

A. Sample A

16. Which of the following is NOT a rule for constructing a simple frequency distribution? A. The number of intervals should equal the number of values measured. B. Each interval is equidistant. C. No interval overlaps. D. At least five intervals are included.

A. The number of intervals should equal the number of values measured.

20. Which of the following is the best explanation for why the standard deviation is almost always reported with the mean? A. The standard deviation measures the spread of scor es from the mean, so it is important to know both the mean and the standard deviation. B. The standard deviation is also a measure of central tendency, so it is important to report this value with the mean. C. The mean and standard deviation estimate basically the same thing, so these values are typically reported together. D. This is not true; the standard deviation is rarely reported with the mean.

A. The standard deviation measures the spread of scor es from the mean, so it is important to know both the mean and the standard deviation.

6. A researcher records the following data for the number of dreams recalled during a night of sleep for 10 college students: 3, 2, 4, 4, 3, 1, 1, 0, 2, and 0. Is the mean equal to the median in this example? A. Yes. B. No; the median is larger than the mean. C. No; the mean is larger than the median. D. There is not enough information to answer this question.

A. Yes.

18. A researcher measures the time (in seconds) that it tak es children to complete a basic reading skills task. What type of graphical display would be most appropriate for summarizing the frequency of children falling into different intervals of time? A. histogram B. bar chart C. pie chart

A. histogram

2. Procedures that allow researchers to infer or generalize observations made with samples to the larger population from which they were selected best describes ______. A. inferential statistics B. sample statistics C. descriptive statistics D. population parameters

A. inferential statistics

9. An animal researcher measures the number of times a rat presses a lever located at the right, center, and left of a cage for a food reward. What scale of measurement is the location of lever pressing? A. nominal B. ordinal C. interval D. ratio

A. nominal

7. ______ data describe numeric aspects of phenomena; whereas ______ data describe nonnumeric aspects of data. A. quantitative; qualitative B. qualitative; quantitative C. continuous; discrete D. discrete; continuous

A. quantitative; qualitative

If a portion of people from a population are asked to complete an assessment, then the average score among that group of people would be considered a ______. A. sample mean B. population mean C. median split D. modal mean

A. sample mean

3. Researchers measure data in a ______ to learn more about individuals in the larger ______ of interest. A. sample; population B. statistic; inference C. population; sample D. inference; statistic

A. sample; population

18. Each deviation in the numerator for variance is squared because ______. A. without squaring each deviation, the solution for SS would be zero B. this inflates the value for variance, making it more accurate C. without squaring each deviation, the solution could be negative

A. without squaring each deviation, the solution for SS would be zero

6. ______ are measured in whole units or categories that are not distributed along a continuum. A. Continuous data B. Discrete data C. Quantitative data D. Open-ended data

B. Discrete data

7. A researcher records the following data for the time (in seconds) it takes five rats to cross an electrical grid to obtain reinforcement on the other side: 12, 9, 13, 4, and 12. Is the mean equal to the mode in this example? A. Yes. B. No; the mode is larger than the mean. C. No; the mean is larger than the mode. D. There is not enough information to answer this question.

B. No; the mode is larger than the mean.

15. A researcher distributes frequencies into the following intervals: 3 -6, 7 -10, 11-15, 16-18, 19-22, and 23-26. What is wrong with this frequency distribution? A. The interval width is too small. B. The interval width is unequal. C. The first interval does not begin at 0. D. One interval is an open class.

B. The interval width is unequal.

19. Which characteristic of a histogram implies that it summaries continuous data? A. The data are plotted on the y-axis. B. The vertical bars touch at the upper boundary of each interval. C. The height of the vertical bars are not restricted. D. The x-axis lists data on a nominal scale of measurement.

B. The vertical bars touch at the upper boundary of each interval.

5. What terms refer to the meaning of each of the following measures, respectively: mean, median, and mode. A. middle, most, and average B. average, middle, and most C. average, most, and middle D. most, average, and middle

B. average, middle, and most

10. The distribution of annual household income in the United States is positively skewed. If the median annual income is about $56,000, this implies that the mean annual household income in the United S tates is ______. A. smaller B. larger C. the same D. There is not enough information to answer this question.

B. larger

16. The variance and standard deviation can never be ______. A. zero B. negative C. smaller than the mean D. larger than the mean

B. negative

10. A consultant ranks the five most needed areas of improvement for a local business. What scale of measurement are the rankings? A. nominal B. ordinal C. interval D. ratio

B. ordinal

8. A researcher records 52 scores. What is the median position of these scores? A. the 26th score in numeric order B. the average of the 26th and 27th scores in numeric order C. the 27th score in numeric order D. It's not possible to know this without the raw scores.

B. the average of the 26th and 27th scores in numeric order

14. Regardless of the number of scores in a distribution, the range only includes ______ score(s) in its calculation. A. one B. two C. at most two D. the average

B. two

19. A researcher records the following scores on a working memory quiz for two samples. Which sample has a larger standard deviation? Sample A: 2, 3, 4, 5, 6, 7, and 8 Sample B: 4, 5, 6, 7, 8, 9, and 10 A. Sample A B. Sample B C. Both samples have the same standard deviation.

C. Both samples have the same standard deviation.

9. A professor grades 120 research papers and reports that the average score was an 80%. What do we know about the sum of the differences of these 120 scores from their mean of 80%? A. The sum of the differences is minimal. B. The sum of the differences is 80%, the same as the mean. C. The sum of the differences is equal to zero. D. It is impossible to k now without knowing each of the 120 scores.

C. The sum of the differences is equal to zero.

3. When would it be appropriate to calculate a population mean? A. When data are measured for a portion of individuals from a population. B. When the sample mean is not available. C. When data are measured for all members of a population. D. When it is not possible to measure all data in a population.

C. When data are measured for all members of a population.

17. A researcher wants to determine how many participants will take less than 24 s to complete a cognitive performance task. If he constructs a frequency distribution for these data, what type of distribution would be most appropriate to answer his question ? A. a simple frequency distribution B. a relative frequency distribution C. a cumulative frequency distribution from the bottom up D. a cumulative frequency distribution from the top down

C. a cumulative frequency distribution from the bottom up

2.The mathematical term ∑ X is the numerator for ______. A. the population mean B. the sample mean C. both population mean and sample mean D. None; this term is not in the numerator for any calculation.

C. both population mean and sample mean

1. The use of tables and graphs to summarize data is an example of ______. A. inferential statistics B. interpretation C. descriptive statistics D. generalization

C. descriptive statistics

11. A researcher measures the body temperature (in degrees Fahrenheit) of participants immediately before and immediately following sleep. Temperature is on what scale of measurement? A. nominal B. ordinal C. interval D. ratio

C. interval

4. The ______ is the sum of all scores (in a sample or population) divided by the number of scores summed. A. mode B. median C. mean D. range

C. mean

8. Each of the following is an example of quantitative data, except ______. A. weight in ounces B. income in dollars C. political affiliation D. age in years

C. political affiliation

13. To determine the interval width, we divide the ______ by the number of intervals. A. observed range B. exclusive range C. real range D. all of these

C. real range

13. The mode can be used with the mean to describe which of the following variables? A. rankings B. gender C. the winning percentage of teams in a league D. all of these

C. the winning percentage of teams in a league

14. As a general rule, a simple frequency distribution should have between ______. A. 3 and 6 intervals B. 2 and 10 intervals C. 8 and 12 intervals D. 5 and 15 intervals

D. 5 and 15 intervals

15. A researcher records the time in seconds it takes a sample of participants to walk al one through a dark portion of campus. The researcher computes SS = 1,200. Assuming that a sample of 25 participants was observed in this study, what is the standard deviation for these data? A. 48 s B. 50 s C. 6.9 s D. 7.1 s

D. 7.1 s

4. Researchers rarely have access to entire populations. How do researchers reso lve this limitation? A. They do not need to resolve this; it is not a limitation at all. B. They record data from an entire population of people to make inferences concerning characteristics in a sample. C. They record data from as many persons in a popula tion as possible to draw conclusions concerning only those individuals. D. They record data from a sample of people in the larger population in order to make inferences concerning characteristics in that larger population.

D. They record data from a sample of people in the larger population in order to make inferences concerning characteristics in that larger population.

11. The mean is an appropriate measure of central tendency for ______. A. data that are unimodal and symmetrically distributed B. data tha t are on an interval or ratio scale C. data in which the mean, median, and mode are equal D. all of these

D. all of these

12. The median is an appropriate measure of central tendency for ______. A. data that are positively skewed B. data that are negatively skewed C. data that are on an ordinal scale D. all of these

D. all of these

20. Which of the following is a type of graphical display used to summarize qualitative, discrete data? A. bar chart B. pie chart C. histogram D. both bar chart and pie chart Ans: D

D. both bar chart and pie chart

12. A researcher compares the amount of college debt (in dollars) that undergraduate students incur up to their 4- year degree. Colleg e debt is on what scale of measurement? A. nominal B. ordinal C. interval D. ratio

D. ratio