Psychology 311 Exam 1
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
The ________ is an arithmetic mean of a weighted or disproportionate set of scores. A) mean B) weighted mean C) median D) mode
B) weighted mean
A researcher records the following scores for an Olympic gymnast following her routine: 9.9, 9.8, 9.6, 9.5, 9.7, 9.1, 8.9, and 9.8. What is the range for the scores? A) 1.0 (9.9 to 8.9) B) 0.3 (9.8 to 9.5) C) 0.5 (9.6 to 9.1) D) It is not possible to compute a range with an even number of scores.
A) 1.0 (9.9 to 8.9)
A researcher decides to split scores on an exam into quartiles. She determines that a score of 64 is at the 25th percentile, a score of 74 is at the 50th percentile, and a score of 80 is at the 75th percentile. What is the interquartile range (IQR) for these data? A) 16 B) 10 C) 6 D) There is not enough information to answer this question.
A) 16
A researcher computes the computational formula for SS, as finds that x = 39 and x2 = 271. If this is a sample of 6 scores, then what would SS equal using the definitional formula? A) 17.5 B) 3.5 C) 232 D) not possible to know because the sample mean is not given
A) 17.5
A researcher computes the definitional formula for SS, as finds that (x-M) = 112. If this is a sample of 20 scores, then what would the value of population variance be using the computational formula? A) 5.6 B) 5.9 C) 112 D) not possible to know because the scores are not given
A) 5.6
Fill in the missing values for A and B in this frequency distribution table: Intervals Frequency 6.0-6.6 12 5.3-5.9 7 4.6-5.2 B 3.9-4.5 10 A-3.8 8 =50 A) A = 3.2, B = 13 B) A = 3.1, B = 14 C) A = 3.3, B = 13 D) There is not enough information to complete this table.
A) A = 3.2, B = 13
The correct order of operations in math is: A) parentheses, roots, exponents, multiplication, division, addition, and subtraction B) addition, subtraction, parentheses, roots, exponents, multiplication, and division C) parentheses, roots, multiplication, division, addition, subtraction, and exponents D) exponents, multiplication, division, parentheses, roots, addition, and subtraction
A) Parentheses, Roots, Exponents, Multiplication, Division, Addition, and Subtraction
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) 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
A researcher records the number of classroom interruptions during each of two class sessions. Which session has the largest standard deviation? Session A: 12, 15, 18, 24, and 30 Session B: 8, 10, 12, 16, and 20 A) Sample A B) Sample B C) Both samples have the same standard deviation.
A) Sample A
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.
A researcher records the number of children at a local school from single-, divorced-, and married-parent homes. This frequency data would be best displayed as a A) bar chart B) frequency polygon C) histogram D) ogive
A) bar chart
Adding the same constant to each score in a distribution (or subtracting the same constant from it) will A) cause the mean to change by that constant B) not change the mean at all because the same constant was added to or subtracted from each score
A) cause the mean to change by that constant
Each of the following are interval scale measurements, except A) duration of sleep (in hours) B) marital satisfaction ratings on a 5-point rating scale C) the latitude and longitude of birth for those suffering from schizophrenia D) the body temperature (in degrees Fahrenheit) increase during exercise
A) duration of sleep (in hours)
Interval scales of measurement A) have equidistant scales B) have a true zero C) both a and b
A) have equidistant scales
A graphical display for grouped frequency distributions with continuous data is called a A) histogram B) bar chart C) pie chart D) scatter gram
A) histogram
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
The sum of the squared differences of scores from their mean is A) minimal B) zero C) negative D) negligible
A) minimal
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) population parameter B) sample statistic C) inferential statistic D) time trial
A) population parameter
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
Which of the following distributions has the largest variability? A) scores: 1, 3, 6, 9, and 12 B) scores: 22, 24, 26, 28, and 30 C) scores: 2, 3, 4, 5, and 6 D) scores: 1, 2, 3, 4, and 5
A) scores: 1, 3, 6, 9, and 12
Bar charts are a lot like histograms, except A) the bars displayed in the graph do not touch B) the bar chart summarizes quantitative data C) the bar chart summarizes continuous data D) all of the above
A) the bars displayed in the graph do not touch
A student scores in the 80th percentile on an exam. What does this mean in comparison to all other students? A) the student scored higher than 80% of all others who took the exam B) the student scored worse than 80% of all others who took the exam C) Of all those who took the exam, only 80% of them completed it D) the student would score the same grade on the exam 80% of the time
A) the student scored higher than 80% of all others who took the exam
An interquartile range removes A) the top and bottom 25% of scores in a distribution before calculating range B) scores above only the 75th percentile before calculating range C) scores below only the 25th percentile before calculating range D) all of the above
A) the top and bottom 25% of scores in a distribution before calculating range
A percentile point is A) the value of a score on a measurement scale below which a specified percentage of scores in a distribution fall B) a summary display that distributes the sum of percentages across a series of intervals C) an interval with no defined upper or lower boundary D) the range of values contained in each interval of a grouped frequency distribution
A) the value of a score on a measurement scale below which a specified percentage of scores in a distribution fall
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 D) both A and C
A) without squaring each deviation, the solution for SS would be zero
A researcher records the time in seconds it takes a sample of participants to walk alone through a dark portion of campus. The researcher computes SS = 1,000. Assuming that a sample of 11 participants was observed in this study, what is the standard deviation for these data? A) 1 seconds B) 10 seconds C) 100 seconds D) 1000 seconds
B) 10 seconds
A researcher computes the computational formula for SS, as finds that x = 22 and x2 = 126. If this is a sample of 4 scores, then what would SS equal using the definitional formula? A) 4 B) 5 C) 104 D) not possible to know because the sample mean is not given
B) 5
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.
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 class interval does not begin at 0. D) One interval is an open class.
B) The interval width is unequal.
A researcher reports that "the average shopper in the sample (n = 12) purchased $65.00 worth of items ( = $65.00) during a busy shopping day." What mistake was made is this citation? A) None; this citation is written appropriately. B) The sample mean is written using the wrong notation. C) The sample size is written using the wrong notation. D) both B and C
B) The sample mean is written using the wrong notation.
What terms refer to 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
A researcher selects a sample of 24 participants and has them complete a survey on dating preferences. In this example, what are the degrees of freedom for sample variance and what does this figure represent? A) df = 24; it represents the number of scores that are free to vary in a sample. B) df = 23; it represents the number of scores that are free to vary in a sample. C) df = 23; dividing SS by df makes the sample variance a biased estimator of the population variance. D) df = 24; dividing SS by df makes the sample variance an unbiased estimator of the population variance.
B) df = 23; it represents the number of scores that are free to vary in a sample
Which of the following research designs is used to determine the causes of behavior that help to explain why the behavior occurs? A) correlational B) experimental C) quasi-experimental D) all of the above
B) experimental
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) increase C) remain the same D) become negative
B) increase
The range of scores in each interval of a grouped frequency distribution is called the A) simple frequency B) interval width C) real range D) grouped data
B) interval width
In the stem-and-leaf display, each number to the right of the vertical line is referred to as a ________; the numbers to the left of the vertical line are called the ________. A) stem; leaf B) leaf; stem C) digit; place D) place; digit
B) leaf; stem
The ________ is the middle value in a distribution of scores that are listed in numeric order. A) mean B) median C) mode D) range
B) median
The variance and standard deviation can never be A) zero B) negative C) smaller than the mean D) larger than the mean
B) negative
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
To construct a pie chart, first distribute the data as A) cumulative percentages B) relative percentages C) cumulative frequencies D) cumulative relative percentages
B) relative percentages
A characteristic (usually numeric) that describes a sample is called a A) sample B) sample statistic C) Population D) population parameter
B) sample statistic
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
All other things being equal (so assuming that the value of SS never changes), as sample size increases, A) the degrees of freedom for sample variance decrease B) the value of sample variance decreases C) the value in the numerator for sample variance increases D) the value in the denominator for sample variance decreases
B) the value of sample variance decreases
A researcher reports that 12 persons in a sample of 60 reported getting between 4 and 6 hours of sleep per night. What is the relative percentage for this interval? A) 24% B) 22% C) 20% D) There is not enough information to answer this question.
C) 20%
The following is a simple frequency distribution table. If we convert this frequency distribution to relative percentages, which of the following gives the corresponding percentages in each interval listed from the top down. Intervals Frequency 44-46 6 41-43 4 38-40 5 35-37 10 32-34 5 =30 A) 20%, 33%, 50%, 67%, 100% B) 0.2, 0.13, 0.17, 0.33, 0.17 C) 20%, 13%, 17%, 33%, 17% D) 6, 10, 15, 25, 30
C) 20%, 13%, 17%, 33% 17%
A researcher records the sound (in decibels) during a series of lessons taught by a substitute teacher at a local elementary school. In his study, he found that the sound was 80±6 (M±SD) decibels. Assuming the data are normally distributed, which of the following is an appropriate conclusion? A) 68% of classes were between 68 and 80 decibels. B) 5% of classes were louder than 68 decibels. C) 95% of classes were between 68 and 92 decibels. D) all of the above
C) 95% of classes were between 68 and 92 decibels.
A researcher records the following scores on a working memory quiz for two samples. Which sample has the largest 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.
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 small (close to 0) because scores are approximately the same. D) It is very large (much greater than 0) because 3 is an outlier in the data.
C) It is very small (close to 0) because scores are approximately the same.
State the problem with this simple frequency distribution. Intervals Frequency 8-10 4 6-8 7 4-6 3 2-4 6 0-2 9 A) The interval width is too small. B) The interval width is unequal. C) The class intervals overlap. D) The number of intervals is too small.
C) The class intervals overlap.
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 know without knowing each of the 120 scores.
C) The sum of the differences is equal to zero.
Which of the following statements about a weighted mean is true. A) The weighted mean is always equal to the arithmetic mean. B) The weight mean can only be reported id the sample size is equal in each group. C) The weighted mean is used to compute the combined mean for two or more samples of scores in which the number of scores in each sample is disproportionate or unequal. D) The weighted mean is heavier than an arithmetic mean.
C) The weighted mean is used to compute the combined mean for two or more samples of scores in which the number of scores in each sample is disproportionate or unequal.
A researcher wants to determine how many participants will take less than 24 seconds 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
The mathematical term x is the numerator for A) the population mean B) the sample mean C) both A and B D) None; this term is not in the numerator for any calculation.
C) both A and B
________ is the variable that is believed to change in the presence of the independent variable. A) Independent variable B) Quasi-independent variable C) Dependent variable
C) dependent variable
The scale of measurement a researcher uses A) depends on whether a sample or population is being studied. B) depends on whether the researcher wants to only report descriptive statistics or also report inferential statistics C) determines the type of inferential statistics that can be done D) must be able to measure continuous variables
C) determines the type of inferential statistics that can be done
Statistical analysis allows researchers to A) collect data B) claim that an observation is scientific C) evaluate scientific observations D) study physical phenomena but not behavior
C) evaluate scientific observations
The three steps for constructing a simple frequency distribution are A) find the observed range, find the interval width, and construct the frequency distribution B) find the real range, count the scores, and construct the frequency distribution C) find the real range, find the interval width, and construct the frequency distribution D) all of the above
C) find the real range, find the interval width, and construct the frequency distribution
Which of the following requires the calculation of a real range? A) frequency distributions for categorical B) frequency distributions for ungrouped data C) frequency distributions for grouped data D) frequency distributions that do not use real data
C) frequency distributions for grouped data
A researcher records the hospital admission rates for coronary heart disease at 10 local hospitals. She finds that 2 different hospitals had the highest overall rates of hospital admissions. Which measure of central tendency did this researcher use to describe these data? A) mean B) median C) mode D) range
C) mode
The ________ is the value that occurs most often or at the highest frequency in a distribution. A) mean B) median C) mode D) range
C) mode
Three key elements of control that allow researchers to draw cause-and-effect conclusions are A) randomization, manipulation, and variation B) assignment, manipulation, and comparison/control C) randomization, manipulation, and comparison/control D) randomization, condition, and comparison/control
C) randomization, manipulation, and comparison/control
A researcher asks participants to estimate the height (in inches) of a statue that was in a waiting area. The researcher records the following estimates: 40, 46, 30, 50, and 34. If the researcher removes the estimate of 40 (say, due to an experimenter error), then the value of the mean will____ (Hint: Calculate the mean first!) A) decrease B) increase C) remain the same D) become negative
C) remain the same
You are interested in measuring the construct, reinforcement. Which of the following measures for this construct is quantitative and continuous? A) the number of rewards received B) the type of reward (food, money) C) the size of a reward in grams D) the rating of a reward on a scale from 1 (not reinforcing) to 7 (very reinforcing)
C) the size of a reward in grams
When would a researcher calculate a population mean? A) when data are measured for of a portion of individuals from a population B) when the sample mean it 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
(blank) A) B) C) D)
D)
A researcher selects a sample of 6 males and 11 females. She asks participants to rate the likelihood they would do female-stereotyped jobs (such as nursing or school teaching) on a scale from 1 = not likely at all to 5 = very likely. Men indicated that they would be less likely to do these jobs (M = 2.1) compared with women (M = 4.3). What is the weighted mean for this entire sample of 17 participants? A) 2.1 B) 4.3 C) 3.2 D) 3.5
D) 3.5
What is the percentile point at the 80th percentile in the following distribution? Frequency Percentile Rank 9-11 100% 6-8 80% 3-5 40% 0-2 20% A) 2 B) 6 C) 7 D) 8
D) 8
Which of the following is NOT a characteristic of the mean? A) Add a score above the mean and the mean will increase. B) Add a score below the mean and the mean will decrease. C) Delete a score below the mean and the mean will increase. D) Delete a score above the mean and the mean will increase.
D) Delete a score above the mean and the mean will increase.
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 interval width is unequal. C) The class intervals overlap. D) One interval is an open class.
D) One interval is an open class.
A researcher distributes frequencies into the following classes: absent, tardy, present. What type of data are distributed? A) nominal data B) qualitative data C) ungrouped data D) all of the above
D) all of the above
A simple frequency distribution A) can be used to summarize grouped data B) can be used to summarize ungrouped data C) summarizes the frequency of scores in a given category or range D) all of the above
D) all of the above
Descriptive statistics are procedures used to A) summarize a set of scores or observations B) organize a set of scores or observations C) make sense of a set of scores or observations D) all of the above
D) all of the above
The mean is an appropriate measure of central tendency for A) data that are normally distributed B) data that are on an interval or ratio scale C) data in which the mean, median, and mode are equal D) all of the above
D) all of the above
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 the above
D) all of the above
The mode is an appropriate measure of central tendency for A) data that are bimodal B) use with other measures of central tendency C) data that are on a nominal scale D) all of the above
D) all of the above
The sample variance is: A) an unbiased estimator of the population variance B) associated with n - 1 degrees of freedom C) computed by dividing SS by df D) all of the above
D) all of the above
When cumulating frequencies from the top down, the data are discussed in terms of A) greater than B) at or above C) at least D) all of the above
D) all of the above
Which of the following is a type of graphical display used to summarize quantitative, continuous data? A) histogram B) frequency polygon C) ogive D) all of the above
D) all of the above
Which of the following is consistent with the empirical rule? A) 68% of all scores lie within one standard deviation of the mean. B) 95% of all scores lie within two standard deviations of the mean. C) 99.7% of all scores lie within three standard deviations of the mean. D) all of the above
D) all of the above
Which of the following is true the computational formula for variance? A) The computational formula will always produce the same solution as the definitional formula (give or take rounding errors). B) It is a short-cut method for calculating variance when the population or sample size is large. C) It is derived mathematically from the definitional formula. D) all of the above
D) all of the above
Qualitative data varies by ________; quantitative data varies by ________. A) level; value B) value; level C) amount; class D) class; amount
D) class; amount
The definitional formula ______ the computational formula for SS. A) estimates B) explains C) diminishes D) equals
D) equals
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) the number of partners B) the spouse C) Lying D) Forgiveness
D) forgiveness
A characteristic (usually numeric) that describes a population is called a A) Sample B) sample statistic C) Population D) population parameter
D) population parameter
A researcher compares the amount of college debt (in dollars) that undergraduate students incur up to their four-year degree. College debt is on what scale of measurement? A) Nominal B) Ordinal C) Interval D) Ratio
D) ratio
Which of the following is an example of a distribution with NO variability? A) scores: 3, 5, 4, 4, 5, and 3 B) scores: 3, 3, 3, 3, 33, and 3 C) scores: 1, 2, 3, 4, 5, and 6 D) scores: 5, 5, 5, 5, 5, and 5
D) scores: 5, 5, 5, 5, 5, and 5
You are interested in measuring the construct, work expertise. Which of the following measures for this construct is quantitative and discrete? A) the total time in hours spent working at a company B) the job title a person holds in a company C) the percent of correct responses on a work expertise survey D) the number of employees that work under an employee
D) the number of employees that work under an employee
Which of the following measures of attraction is an example of a ratio scale measurement? A) a rating of attraction from most attractive to least attractive B) a 6-point rating scale from 1 (attractive) to 6 (unattractive) C) the status of the relationship (acquaintance, dating, married) D) the physical proximity (in feet and inches) between two romantic partners
D) the physical proximity (in feet and inches) between two romantic partners
