Statistics Exam 1
___ is the variable that is believed to change in the presence of the independent variable
Dependent variable
Which of the following terms are least likely to be used to describe qualitative data?
Numeric
Which of the following requires the calculation of a real range?
frequency distributions for grouped data
The sum of relative frequencies for each interval is
1.00
A researcher finds that 12% of participants makes between 3-5 visits to a physician each year. What are the real limits for this interval.
2.5-5.5
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?
20%
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?
3.5
As a general rule, a simple frequency distribution should have between
5 and 20 intervals
A researcher records the following scores: 5, 3, 7, 6, 2, 8, 0, and 1. In terms of these data, the sum of the squared differences of scores from their mean is
60
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 cumulative frequency distribution from the bottom up
A psychologist wants to know how many of her clients continue with therapy for at least 12 days. If she constructs a frequency distribution for these data, what type of distribution would be most appropriate to answer her question?
A cumulative frequency distribution from the top down
A percentile is also called a
percentile point
When cumulating frequencies from the bottom up, the data are discussed in terms of
At most, less than, and at or below
What terms refer to each of the following measures, respectively: mean, median, and mode
Average, middle, and most
Which of the following is a type of graphical display used to summarize qualitative, discrete data?
Bar chart, pie chart, and histogram
Each of the following are interval scale measurements, except
DURATION OF SLEEP (IN HOURS), MARITAL SATISFACTION RATINGS ON 5-POINT RATING SCALE, the latitude and longitude of birth for those suffering from schizophrenia, the body temperature (in degrees Fahrenheit) increase during the exercise
The median is an appropriate measure of central tendency for
Data that are positively skewed, negatively skewed, or on an ordinal scale
Which of the following is NOT a characteristic of the mean?
Delete a score above the mean and the mean will increase
A researcher records the number of votes for each of five candidates running for class president. Based on her presentation of the following results, what type of statistics did she use? (chart with number of votes next to each candidate)
Descriptive statistics
Quantitative measures can be
Discrete and continuous data
___ are measured in whole units or categories that are not distributed along a continuum
Discrete data
Recording the number of dreams recalled is an example of ___ data; whereas recording the time (in minutes) spent in a dream stage of sleep is an example of ___ data
Discrete; continuous
Which of the following research designs is used to determine the causes of behavior that help to explain why the behavior occurs?
Experimental
Three research methods common to research in the behavioral sciences are
Experimental, quasi-experimental, and correlational
A ___ is plotted at the midpoint of each interval, whereas a ___ is plotted at the upper boundary of each interval
Frequency polygon; ogive
When cumulating frequencies from the top down, the data are discussed in terms of
Greater than, at or above, and at least
A researcher measures the mean time (in seconds) it takes two groups of children to complete an activity task. She finds that Group A (M = 22 seconds) completed the task more quickly than Group B (M = 36 seconds). She then computes a weighted mean for both groups combined and calculates = 26. Based on the information provided, which group had a larger sample size?
Group A
A researcher summarizes a set of frequency data into five intervals. This is an example of a frequency distribution for
Grouped data
A researcher measures the weight (in ounces) of newborn infants in the month of March. What type of graphical display would be the most appropriate for summarizing the frequency of infants falling into different intervals of weight?
Histogram
Which of the following is a type of graphical display used to summarize quantitative, continuous data?
Histogram, frequency polygon, ogive
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
Increase
Procedures that allow researchers to infer or generalize observations made with samples to the larger population from which they were selected best describes
Inferential statistics
A researcher measures the body temperature (in degrees Fahrenheit) of participants immediately before and immediately following sleep. Temperature is on what scale of measurement?
Interval
The size of a population is symbolized as ____, whereas the size of a sample is symbolized as ___
N; n
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?
No, the mode is larger than the mean
To measure attraction, a researcher records the following data for the distance (in inches) between two persons sitting in a waiting room: 46, 32, 10, 23, 18, 46, and 60. Is the mode equal to the median in this example?
No; the mode is larger than the median
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?
Nominal
An education counselor records the number of high school graduates enrolled in community colleges, four-year colleges, and universities. What scale of measurement is the type of college?
Nominal
A researcher distributes frequencies into the following classes: absent, tardy, present. What type of data are distributed?
Nominal, qualitative, and ungrouped data
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?
One interval is an open class
A consultant ranks the five most needed areas of improvement for a local business. What scale of measurement are the rankings?
Ordinal
A movie critic rates a movie on a scale from one (lowest) to four (highest) stars. What scale of measurement are the ratings?
Ordinal
___ data describe numeric aspects of phenomena; whereas ___ data describe nonnumeric aspects of data
Quantitative; qualitative
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?
Ratio
To determine the interval width, we divide the ___ by the number of intervals
Real range
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?
Researcher B
___ refer to how the properties of numbers can change with different uses
Scales of measurement
Descriptive statistics are procedures used to
Summarize a set of scores or observations, organize a set of scores or observations, and make sense of a set of scores or observations
Which of the following is NOT a rule for constructing a simple frequency distribution?
THE NUMBER OF INTERVALS SHOULD EQUAL THE NUMBER OF VALUES MEASURED, each interval is equidistant, no class interval overlaps, values are rounded to the same degree of accuracy measured in the original data
A researcher records 52 scores. What is the median position of these scores?
The average of the 26th and 27th scores in numeric order
A staff member records the number of victories (per 10-game season) for a new football coach during his first three seasons with a team. The coach won 1, 3, and 8 games respectively over the three seasons. Which conclusion is appropriate?
The football coach won an average of four games per season, the coach won a median of three games per season, and the coach won 40% of his games during his first three seasons
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?
The interval width is unequal
Which of the follow best describes an independent variable?
The manipulated variable
Which of the following best describes a dependent variable?
The measured behavior
A researcher reports, "the average patron (n = 22) in a local bar consumed more than twice the number of drinks (per day) on weekends (M = 5.4 drinks) compared to weekdays (M = 2.3 drinks)." Although not stated directly, how do we know that the patrons in this study constitute a sample, and not a population of patrons at this local bar?
The notation for a sample mean was used and the notation for sample size was used
You are interested in measuring the construct, work expertise. Which of the following measures for this construct is quantitative and discrete?
The number of employees that work under an employee
What is the corresponding percentile of a percentile point?
The percentile rank
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?
The sample mean is written using the wrong notation
You are interested in measuring the construct, reinforcement. Which of the following measures for this construct is quantitative and continuous?
The size of a reward in grams
A student scores in the 80th percentile on an exam. What does this mean in comparison to all other students?
The student scored higher than 80% of all others who took the exam
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%?
The sum of the differences is equal to zero
Which characteristic of a histogram implies that it summarizes continuous data?
The vertical bars touch at the upper boundary of each interval
Which of the following statements about a weighted mean is true?
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
Researchers rarely have access to entire populations. How do researchers resolve this limitation?
They record data from a sample of people in the larger population in order to make inferences concerning characteristics in that larger population
The mode can be used with the mean to describe which of the following variables?
Volume in a container
A researcher selects a sample of 6 professors, 6 students, and 6 administrators at a local school and has them rate the effectiveness of an innovative new teaching style. In this example, is it possible that the weighted mean ratings will equal the arithmetic mean for the entire sample of 18 participants?
Yes, because the sample sizes are equal in this example
A percentile is
a percentile point
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 population of moviegoers who paid to see the movie in a theater
Which of the following will decrease the value of the mean?
adding a score below the mean
A population can be ___ group of interest to a researcher
any
Grouped data can be distributed
as a range of values, with upper and lower boundaries, and into intervals
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
bar chart
A simple frequency distribution
can be used to summarize grouped data, ungrouped data, or frequency of scores in a given category or range
Ungrouped data can be distributed as
categories
Adding the same constant to each score in a distribution (or subtracting the same constant from it) will
cause the mean to change by that constant
Multiplying or dividing each score in a distribution by the same constant will
cause the mean to change by that constant
Qualitative data varies by ____; quantitative data varies by ___
class; amount
The procedure of converting a categorical variable to numeric values, is called:
coding
___ are measured along a continuum at any place beyond the decimal point
continuous data
The mode is an appropriate measure of central tendency for
data that are bimodal, use with other measures of central tendency, and data that are on a nominal scale
The mean is an appropriate measure of central tendency for
data that are normally distributed, data on an interval or ratio scale, and data in which the mean, median, and mode are equal
The use of tables and graphs to summarize data is an example of
descriptive statistics
A health practitioner measures the heart rate (in BPM) of patients under low, moderate, and high stress levels. HR can be best described as
discrete data
The mean would be used to describe which of the following variables?
distance traveled in miles
Statistical analysis allows researchers to
evaluate scientific observations
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
experimental
The three steps for constructing a simple frequency distribution are
find the real range, find interval width, and construct the frequency distribution
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
forgiveness
Interval scales of measurement
have equidistant scales
A graphical display for grouped frequency distributions with continuous data is called a
histogram
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?
histogram
___ is the variable in an experiment that is manipulated between conditions being observed
independent variable
The range of scores in each interval of a grouped frequency distribution is called the
interval width
Grouped data are distributed into ___, whereas ungrouped data are distributed into ___
intervals; categories
The distribution of personal income for U.S. citizens is positively skewed. If the median annual income is $44,000, this implies that the mean annual income is
larger
A researcher records the time (in seconds) that participants arrive late for a scheduled research study. Assuming these data are normally distributed, which measure of central tendency is most appropriate to describe these data?
mean
The ___ is the sum of all scores (in a sample or population) divided by the number of scores summed
mean
A researcher asks adult participants to rank their top five favorite songs from their childhood. Based on the scale of measurement described, which measure of central tendency is most appropriate to describe these data?
median
The ___ is the middle value in a distribution of scores that are listed in numeric order
median
The sum of the squared differences of scores from their mean is
minimal
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?
mode
The ___ is the value that occurs most often or at the highest frequency in a distribution
mode
A researcher records the following data for the number of times an interviewer is interrupted during a series of interviews: 0, 0, 3, 2, 5, 3, 0, 8, 0, 2, 1, and 1. Is the mode equal to the median in this example?
no, the median is larger than the mode
A researcher records the following data for the number of complaints filed (per day) following a controversial policy change at a local business: 3, 8, 5, 0, 4, 6, 2, 1, 1, 4, 2, and 0. Is the mean equal to the median in this example?
no; the mean is larger than the median
State the four scales of measurement in order from least to most informative
nominal, ordinal, interval, ratio
Which graphical display lists percentages and not original scores?
ogive
A cumulative percentage summary that indicates the percentage of scores at or below a given value is called a
percentile rank
The ___ is the percentage of scores with values that fall below a specified score in a distribution, is called the:
percentile rank
A characteristic (usually numeric) that describes a population is called a
population parameter
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
population parameter
Recording whom students study with describes ___ types of data; whereas recording the number of hours spent studying per week describes ___ types of data
qualitative; quantitative
Grouped data are to ungrouped data as
quantitative is to qualitative
3 key elements of control that allow researchers to draw cause-and-effect conclusions are
randomization, manipulation, and comparison/control
The median would be used to describe which of the following variables?
rankings
To construct a pie chart, first distribute the data as
relative percentages
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
remain the same
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
sample mean
Which type of mean is used to describe a portion of individuals in a given population?
sample mean
A characteristic (usually numeric) that describes a sample is called a
sample statistic
A researcher records the time it takes to complete a memory task in a sample of 25 participants. He finds that the average participant completed the test in 43 seconds. The average time to complete this task is called a
sample statistic
Researchers measure data in a ___ to learn more about individuals in the larger ___ of interest
sample; population
Which of the following describes a descriptive statistic?
summarize
Which of the following can be used to estimate the median?
the 50th percentile of a cumulative percentage distribution
A researcher records 17 scores. What is the median position of these scores?
the 9th score in numeric order
Bar charts are a lot like histograms, except
the bars displayed in the graph do not touch
The fact that the sum of the differences of scores from their mean is zero best illustrates that
the mean is the "balance point" of a distribution
Which of the following measures of attraction is an example of a ratio scale measurement?
the physical proximity (in feet and inches) between two romantic partners
The mathematical term ∑x is the numerator for
the population and sample mean
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:
the small group of college students who here observed
A percentile point is
the value of a score on a measurement scale below which a specified percentage of scores in a distribution fall
A relative frequency distribution is appropriate when
there are large frequency counts in each interval
Each of the following is an example of quantitative data, except
weight in ounces, income in dollars, POLITICAL AFFILIATION, age in years
The ___ is an arithmetic mean of a weighted or disproportionate set of scores
weighted mean
When would a researcher calculate a population mean?
when data are measured for all members of a population
A researcher records the following data for how participants rated the likability (on a scale from 1 = not liked at all to 7 = very likable) of an individual who blushed after making a mistake: 5, 4, 7, 6, 6, 4, 6, 7, 2, 5, and 6. Is the mode equal to the median in this example?
yes
A researcher records the following data for the number of different food items chosen by seven participants in a buffet-style setting: 1, 6, 2, 5, 4, 3, and 7. Is the mean equal to the median in this example?
yes
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?
yes
Given the same set of data for a population and sample, would the mean for both data sets be equal?
yes, this would be true anytime both data sets are the same
Which of the following is not a symbol used with samples
μ
The population mean is symbolized as ___, whereas the sample mean is symbolized as ___
μ; M