Chapter one,two Intro Stats
Which of the following is a type of graphical display used to summarize quantitative, continuous data? A. histogram B. all of these C. ogive D. frequency polygon
B
A cumulative percentage summary that indicates the percentage of scores at or below a given value is called a ______. A. percentile rank B. cumulative frequency C. relative frequency D. relative percentage
A
A researcher measures the amount of coffee consumed by college students while studying during the final exam week. In her study, she found that students drink 2.3 ± 0.8 (M ± SD) cups of coffee per study session. Assuming the data are normally distributed, which of the following is the most appropriate conclusion? A. Most students drink between 1.5 and 3.1 cups of coffee per study session. B. Most students drink between 0.7 and 2.3 cups of coffee per study session. C. The average student drinks less than 2.3 cups of coffee per study session. D. Most students drink between 2.3 and 3.9 cups of coffee per study session.
A
A researcher reports that "the average shopper in the sample (n = 12) purchased $65.00 worth of items (μ = $65.00) during a busy shopping day." What mistake was made is this citation? A. The sample mean is written using the wrong notation. B. None; this citation is written appropriately. C. Both the sample mean and sample size were written using the wrong notation D. The sample size is written using the wrong notation.
A
Suppose that a researcher is interested in a group of 10 million people who paid to see a movie playing in theaters. In this example, the 10 million moviegoers would be regarded as ______. A. a population of moviegoers who paid to see the movie in a theater B. a sample of moviegoers who paid to see the movie in a theater C. a dependent variable D. an independent variable
A
To determine the interval width, we divide the ______ by the number of intervals. A. real range B. exclusive range C. all of these D. observed range
A
When would it be appropriate to calculate a population mean? A. When data are measured for all members of a population. B. When it is not possible to measure all data in a population. C. When the sample mean is not available. D. When data are measured for a portion of individuals from a population.
A
Which of the following can be used to estimate the median? A. the 50th percentile of a cumulative percentage distribution B. the 50th percentile of a relative percentage distribution C. the mean D. the mode
A
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 the largest variance? A. Both samples have the same variance B. Sample A C. There is not enough information to answer this question. D. Sample B
B
A researcher records the number of children at a local school from single-, divorced-, and married-parent homes. These frequency data would be best displayed as a ______. A. ogive B. bar chart C. histogram D. frequency polygon
B
All other things being equal (so assuming that the value of SS never changes), as sample size increases, ______. A. the value in the numerator for sample variance increases B. the value of sample variance decreases C. the value in the denominator for sample variance decreases D. the degrees of freedom for sample variance decrease
B
Assuming N does not equal n and all data are otherwise the same, how will the value of the sample variance be different from the population variance? A. The sample variance will always be a smaller value than the population variance. B. The sample variance will always be a larger value than the population variance. C. The sample variance, but not the population variance, can be negative. D. The sample variance, but not the population variance, can be zero.
B
Which of the following distributions has the largest variability? A. scores: 22, 24, 26, 28, and 30 B. scores: 1, 3, 6, 9, and 12 C. scores: 1, 2, 3, 4, and 5 D. scores: 2, 3, 4, 5, and 6
B
Which of the following values is NOT needed to compute sample variance using the computational formula, but is needed to compute the definitional formula? A. degrees of freedom B. sample mean C. scores (x) D. sample size
B
the fact that the sum of the differences of scores from their mean is zero best illustrates that ______. A. the mean is equal to zero B. the mean is the "balance point" of a distribution C. the mean is at the center of a distribution D. the mean can never be negative
B
A ______ is plotted at the midpoint of each interval, whereas a ______ is plotted at the upper boundary of each interval. A. histogram; frequency polygon B. frequency polygon; histogram C. frequency polygon; ogive D. histogram; bar chart
C
A researcher measures the time (in seconds) that it takes 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. bar chart B. all of these C. histogram D. scatter gram
C
A researcher records a sample of 30 exam scores and finds that if these data were treated as a population, that the population variance calculation for these data is larger than the sample variance calculation for these same data. Is this outcome for variance possible? A. Not possible to know because the scores are not given. B. Yes, the population variance is usually larger than the sample variance. C. No, the sample variance will be larger because SS is divided by degrees of freedom in the denominator of the variance formula. D. No, the population variance will only be larger when at least 50 scores are recorded.
C
A student scores in the 80th percentile on an exam. What does this mean in comparison to all other students? A. The student would score the same grade on the exam 80% of the time. B. The student scored worse than 80% of all others who took the exam. C. The student scored higher than 80% of all others who took the exam. D. Of all those who took the exam, only 80% of them completed i
C
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. modal mean B. population mean C. sample mean D. median split
C
To construct a pie chart, first distribute the data as ______. A. cumulative relative percentages B. cumulative frequencies C. relative percentages D. cumulative percentages
C
Which of the following is consistent with the empirical rule? A. At least 68% of all scores lie within one standard deviation of the mean. B. At least 95% of all scores lie within two standard deviations of the mean. C. all of these D. At least 99.7% of all scores lie within three standard deviations of the mean.
C
Which of the following will decrease the value of the mean? A. adding a score exactly equal to the mean B. none of these C. adding a score below the mean D. deleting a score below the mean
C
A percentile point is ______. A. a summary display that distributes the sum of percentages across a series of intervals B. the range of values contained in each interval of a grouped frequency distribution C. an interval with no defined upper or lower boundary D. the value of a score on a measurement scale below which a specified percentage of scores in a distribution fall
D
A researcher asks participants to estimate the calories they consume in a meal. The researcher records the following estimates: 450, 426, 310, 500, and 220. If the researcher removes the estimate of 220 (perhaps because the participant drops out of the study), then the value of the mean will ______. A. decrease B. become negative C. remain the same D. increase
D
A researcher distributes frequencies into the following intervals: 1-10, 11-20, 21-30, 31-40, 41-50, and 51 and above. What is wrong with this frequency distribution? A. The interval width is too small. B. The class intervals overlap. C. The interval width is unequal. D. One interval is an open class.
D
A researcher records 17 scores. What is the median position of these scores? A. the average of the 9th and 10th scores in numeric order B. It's not possible to know this without the raw scores. C. the average of the 8th and 9th scores in numeric order D. the 9th score in numeric order
D
A researcher records the following data: 4, 4, 4, 4, and 3. How would you describe the variability of these data? A. It is equal to zero because scores are approximately the same. B. It is negative because 3 is less than the other scores in the distribution. C. It is very large (much greater than 0) because 3 is an outlier in the data. D. It is very small (close to 0) because scores are approximately the same.
D
A(n) ______ is a sample statistic that equals a population parameter on average. A. sum of squares B. biased estimator C. degrees of freedom D. unbiased estimator
D
An interquartile range removes ______. A. scores below only the 25th percentile before calculating range. B. all of these C. scores above only the 75th percentile before calculating range D. the top and bottom 25% of scores in a distribution before calculating range
D
The following is a simple frequency distribution table. Suppose we convert this table to a cumulative frequency distribution. The frequencies in each interval of the cumulative frequency distribution would be Frequency:5,3,2,4,20 A. 6, 10, 12, 15, 20 (bottom-up summary) B.5, 8, 10, 14, 20 (top-down summary) C. It is not possible to summarize the data using a cumulative frequency distribution. D. both A and B, depending on how the data were summarized
D
What terms refer to the meaning of each of the following measures, respectively: mean, median, and mode. A. most, average, and middle B. average, most, and middle C. middle, most, and average D. average, middle, and most
D
Each of the following are interval scale measurements, except ______. A. the body temperature (in degrees Fahrenheit) increase during exercise B. scores on an SAT (scholastic assessment test) C. the latitude and longitude of birth for those suffering from schizophrenia D. duration of sleep (in hours)
duration of sleep in hours
A researcher tests whether the dosage level of some drug (low, high) causes significant differences in health. To do this, the researcher randomly assigns rat subjects to receive a low or high dosage of the drug and records health-related measures in both groups. The type of method described is ______. A. quasi-experimental B. experimental C. correlational D. operational
experimental
Which of the following research designs is used to determine the causes of behavior that help to explain why the behavior occurs? A. quasi-experimental B. correlational C. experimental D. All of these
experimental
A therapist observes that spouses are more likely to forgive their partners for lying to them if they find out the truth from their spouse and not a third party. In this example, the dependent variable is ______. A. lying B. the spouse C. the number of partners D. forgiveness
forgiveness
A movie critic rates a movie on a scale from 1 (lowest) to 4 (highest) stars. What scale of measurement are the ratings? A. interval B. ratio C. ordinal D. nominal
ordinal
A psychologist reviews her notes for all her patients and determines that on average her patients complete therapy in 24 days. The average time to complete therapy among all her patients is called a(n) ______. A. sample statistic B. population parameter C. inferential statistic D. time trial
population parameter
A researcher compares the amount of college debt (in dollars) that undergraduate students incur up to their 4-year degree. College debt is on what scale of measurement? A. interval B. ratio C. ordinal D. nominal
ratio
Researcher A measures academic preparedness as the percent correct responses on an entrance exam; Researcher B measures academic preparedness as the current class rank of students. Which researcher measured academic preparedness as discrete data? A. Researcher B B. no researchers C. Researcher A D. both researchers
researcher B
You are interested in measuring the construct, reinforcement. Which of the following measures for this construct is quantitative and continuous? A. the size of a reward in grams B. the rating of a reward on a scale from 1 (not reinforcing) to 7 (very reinforcing) C. the type of reward (food, money) D. the number of rewards received
size of a reward in grams
A researcher identifies college students as a group of interest to test her hypothesis. She then identifies a few local college students and selects a small group of the local college students to be observed. In this example, the sample is ______. A. the small group of college students who here observed B. all college students C. not clearly identified D. the few local college students
the small group of college students who here observed