Final Exam Psych 210

Weight (in pounds) of an infant

Continuous; quantitative; ratio

Position standing in line

Discrete; quantitative; ordinal

The _______ is the preferred measure of central tendency when a data set has outliers.

Median

Duration of drug abuse (in years)

Continuous; Quantitative; ratio

State whether the variables listed above are quantitative or qualitative

a) quantitative b) quantitative c) Qualitative d) Qualitative

19) To determine whether a new sleeping pill was effective, adult insomniacs received a pill (either real or fake), and their sleeping times were subsequently measured (in minutes) during an overnight observation period. a) identify the dependent variable b) identify the independent variable

a) sleeping times b) the pill

An interval scale ______. Choose one has no true zero is distributed on an equidistant scale is the most informative scale of measurement both A and B

both A and B

Which of the following will decrease the value of the mean for a distribution of scores? Choose one adding a new score above the mean deleting an existing score above the mean adding a new score equal to the mean deleting an existing score below to the mean

deleting an existing score above the mean

is a pie chart typically used to summarize continuous or discrete/categorical data?

discrete/categorical data

Which type of central tendency is always located at the center or in the middle of the distribution?

median

A normal distribution has a mean equal to 5. what is the value of the median and mode in this distribution?

median and mode = 5

The area under a normal curve ranges between 0 and 1 and can never be negative. What type of statistic also has these same characteristics?

probability

A researcher collects the following scores: 1, 2, 3, 4, 5, 6, 7, and 8. What is the range of these scores?

7

A researcher selects a population of eight scores where SS = 72. What is the population variance in this example.

72/8 = 9

6) State the four scales of measurement. Which scale of measurement is the most informative?

Nominal, ordinal, interval, ratio; ratio is the most informative

The notation used in the formulas for sample mean and population mean differs. What notation differs in these formulas?

The term N is used in the denominator for the population mean, and the term n is used in the denominator for the sample mean

A therapist measures the time (in hours) that clients continue a recommended program of counseling.

The time (in hours) is continuous and quantitative

Cumulative frequencies can be added from the top _______ and the bottom ________.

down; up

Suppose that at least 68% of scores in a normal distribution fall between a score of 7 and 10. Using the empirical rule, what is the approximate mean and standard deviation of these data? Choose one mean = 7, standard deviation = 10 mean = 8.5, standard deviation = 3 mean = 8.5, standard deviation = 1.5 mean = 10, standard deviation = 7

mean = 8.5, standard deviation = 1.5

Which value is not needed to find SS using the computational formula? Choose one the sum of scores the sum of squared scores the mean the sample or population size

the mean

T/f: Cumulative relative frequencies are added from the top down or the bottom up

true

A researcher records fives scores: 3, 4, 5, 6, and x. IF the mean in this distribution is 5, then what is the value for x?

x = 7

The population mean is identified by the Greek letter ______; the sample mean is identified by an italicized ______. Choose one µ; Ʃ M; µ µ; M Ʃ; M

µ; M

Cumulative relative frequencies sum to _______ (give or take rounding)

1.00

The median can be used for skewed distributions and ordinal data. Why is the median appropriate for describing ordinal data? Choose one ordinal data are the only type of data that have a median ordinal data are always positively or negatively skewed ordinal data convey direction only (more or less than) ordinal data convey the same information as ratio data

ordinal data convey direction only (more or less than)

Body type (slim, average, heavy)

Discrete; qualitative; nominal

The denominator for sample variance is ______; the denominator for population variance is ______. Choose one N; n − 1 n − 1; N df; N both B and C

both B and C

10) What are the two types of variables that can be quantitative?

continuous and discrete variables

How many standard deviations from the mean will contain at least 99% of data for any type of distribution?

+/- 10 Standard deviations

A researcher measures a data set with a range equal to 12. Which of the following data sets has a range equal to 12? Choose one 2, 5, 3, 12, 8 0, 9, 3, 12, 10, 7 24, 10, 18, 26, 36 7, 13, 12, 16, 20

0, 9, 3, 12, 10, 7

If the smallest score in a distribution is 12 and the largest is 71, then what is the interval width if we create six intervals? 6 9.83 10 12

10

The population variance is 121 What is the standard deviation for this sample?

11

The sample variance is 121. What is the standard deviation for this sample?

11

How many scores are included to compute the range?

2 scores; the largest and the smallest scores in the distribution

If the smallest score in a distribution is 10 and the largest is 32, then what is the real range for these data? 20 21 22 23

23

The frequency of alcohol-related arrests during a single season at a sporting arena ranged from 0 to 17 arrests per game. What is the interval width if you choose to create a frequency distribution with 6 intervals?

3 (17+1)/6

The lower boundaries for the number of tattoos among prison inmates are 1, 4, 7, 10, 13 and 16. List the value for each upper boundary in this distribution.

3, 6, 9, 12, 15, 18

Suppose the population variance for a given population is 36. IF we select all possible samples of a certain size from this population, then, on average, what will be the value of the sample variance?

36

Suppose a normal distribution has a mean of 8 and a standard deviation of 2. What is the range of scores within which at least 95% of scores are contained? Choose one 8-10 4-12 6-10 6-8

4-12

As a general rule, when the number of intervals needed to summarize a data set is smaller than ______, we can leave the data ungrouped. 5 10 15 20

5

What is the recommended number of intervals that should be included in a simple frequency distribution?

5 to 20

Compute the sample standard deviation for the following data: 2, 4, 2, 5, 8, 19, 7, 12, 13, 9, 10, 13, 15, 19, 23, 3, 20, 18, 19, and 10. Choose one 6.430 6.597 41.348 43.524

6.597

From the choices in the question above, which will increase the value of the mean?

A

3) By definition, how is a sample related to a population?

A population is the set of all individuals, items, or data of interest. This is the group about which scientists will generalize. A sample is a set of individuals, items, or data selected from the population of interest.

How do sample mean and population mean differ?

A population mean is the mean for a set of scores in an entire population, whereas the sample mean is the mean for a sample, or subset of scores from a population.

A continuous variable ______. Choose one is measured along a continuum can be measured at any place beyond the decimal point can be measured in whole units or fractional units all of these

All of these

How many scores are free to vary in a sample?

All scores, except one, are free to vary

16) A researcher demonstrates that eating breakfast in the morning cause increased alertness throughout the day. What research design must the researcher have used in this example?

An experiment (if there is cause, there is an experiment)

Which of the following will decrease the value of the mean? a) delete a score below the mean b) add a score below the mean c) add a score exactly equal to the mean d) none of the above

B

Which of the following is a graphical display used to summarize discrete data? frequency polygon ogive histogram bar chart

Bar chart

Why is variance a preferred measure of variability?

Because it includes all scores in its computation

Why is variance, as a measure of variability, preferred to the range, the IQR, and the SIQR?

Because it includes all scores to estimate variability

Landry stated (scaled) data can be validly treated as interval. Explain why data on a rating scale are often treated as interval scale data in the behavioral sciences.

Because the data has no true zero and they are presumed to be equidistant on these scales

A family counselor records the number of sessions required for children to complete counseling following the loss of a family member. The counselor finds that most boys complete counseling in 12 sessions, whereas most girls require 15 sessions to complete counseling. If the data for boys and girls are combined, what type of distribution best describes the combined data?

Bimodal distribution

From the choices in the question above, which will have no effect on the mean?

C

All measures of central tendency have a tendency to be at or near the ______ of a distribution.

Center

List five characteristics of the mean:

Changing an existing score will change the mean adding a new score or removing an existing score will change the mean, unless that value equals the mean adding, subtracting, multiplying, and dividing each score in a distribution by a constant will cause the mean to change by that constant The sum of the differences of scores from their mean is zero The sum of the squared differences of scores from their mean is minimal

The median is an appropriate measure for describing what types of data?

Data that are skewed and ordinal (quantitative)

A qualitative variable varies by ______; a quantitative variable varies by ______. Choose one class; amount amount; class counting; measuring measuring; counting

Class; amount

Temperature (degrees in Farenheit)

Continuous; quantitative; interval

Score (0% to 100% on an exam)

Continuous; quantitative; ratio

Time (in seconds) to memorize a list

Continuous; quantitative; ratio

15) A researcher measures the height and income of participants and finds that taller men tend to earn greater incomes than do shorter men. what type of research method did the researcher use in this example?

Correlation

A __________ is a summary display that distributes the sum of frequencies across a serires of intervals

Cummulative Frequency distribution

An ogive is used to summarize what type of frequency distribution? relative percent percentile rank relative frequency cumulative percent

Cumulative percent

What type of distribution is used to approximate the median?

Cumulative percent distribution

All of the following characteristics are true about a normal distribution except: a) the mean can be any positive or negative number b) the variance can be any positive number c) the shape of the normal distribution is symmetrical d) the tails of a normal distribution touch the x-axis at 3 SD from the mean

D

The mean is a preferred descriptive statistic: a) for describing normal distributions b) for summarizing interval scale measures c) for summarizing ratio scale measures d) all the above

D

Which type of modal distribution would not be described using the mode? a) unimodal b) bimodal c) multimodal d) nonmodal

D

2) What is the difference between data and raw score?

Data describe a set of measurements (made up of raw scores); a raw score describes individual measurements

A behavioral scientist measures attention in a sample of 31 participants. To measure the variance of attention, she computes SS = 120 for this sample. (a) What are the degrees of freedom for variance? (b) Compute the variance and standard deviation.

Degrees of Freedom = 30 s^2 = 4 standard deviation = 2

A researcher summarizes a set of data by describing the score that occurred most often. What type of statistics did the researcher use to summarize these data? Choose one descriptive inferential analytical professional

Descriptive

1) Distinguish between descriptive and inferential statistics:

Descriptive statistics are procedures used to summarize/organize/make sense of data (graphs/tables/single values) Inferential statistics: Procedures that allow us to infer/generalize observations made with the larger population from which they were selected

Political affiliation (Republican, Democrat)

Discrete; qualitative; nominal

Seasons (spring, summer, fall, winter)

Discrete; qualitative; nominal

Sex (male/female):

Discrete; qualitative; nominal

Type of distraction (auditory, visual)

Discrete; qualitative; nominal

A letter grade (A,B,C,D,F)

Discrete; qualitative; ordinal

A college Student's SAT score

Discrete; quantitative; interval

Number of students in your class

Discrete; quantitative; ratiO

Number of dreams recalled

Discrete; quantitative; ratio

Number of errors

Discrete; quantitative; ratio

4) State three commonly used research methods in behavioral science.

Experimental, Quasi-Experimental, and correlational research methods

T/F: Histograms are used to summarize ungrouped data, which is why each vertical rectangle touches the other

False

T/F: When the mean is greater than the mode, the distribution is negatively skewed.

False

T/F: The mean is a preferred measure for describing skewed distributions

False (median)

T/F: qualitative variables can be discrete or continuous

False: only discrete

A researcher records the number of times that 10 students cough during a final exam. He records the following data: 0,0,0,3,3,5,5,7,8, and 11. True or false: In this example, the range will be smaller than the IQR.

False; range = 8 and IQR = 7

Each of the following is a rule for constructing a histogram, except ______. a vertical rectangle represents each interval, and the height of the rectangle equals the frequency recorded for each interval the base of each rectangle begins and ends at the upper and lower boundaries of each interval each rectangle touches adjacent rectangles at the boundaries of each interval frequencies are plotted at the midpoints of each interval and the line connects each plot

Frequencies are plotted at the midpoints of each interval and the line connects each plot

A ________ is a summary display for a distribution of data organized or summarized in terms of how often (or frequently) scores occur.

Frequency distribution

A(n) __________ is a dot-and-line graph plotted at the midpoint of each interval whereas a(n) ________ is a dot and line graph plotted at the upper boundary of each interval

Frequency polygon, ogive

Why is it generally innappropriate to include an open interval in a simple frequency distribution?

Including an open interval can make it difficult to identify if outliers exist in the data

To study NCAA athletes at a local college, a researcher measures behavior in a portion of all athletes at the college. What type of statistics can the research use to draw conclusions about the behavior of all athletes at the college? Choose one descriptive parameter inferential professional

Inferential

8) What is the main distinction between variables on an interval scale and those on a ratio scale?

Interval scale variables do not have a true zero; ratio scale variables have a true zero

A discrete variable ______. Choose one is measured in whole units or categories can be measured at any place beyond the decimal point can be measured in fractional units is measured along a continuum

Is measured in whole units or categories

How do you compute standard deviation?

Take the square root of the variance

Which of the following is true about variability? Choose one it can only be a negative value it is always a positive value or 0 it can range between −1 and +1 it is only important for central tendency

It is always a positive value or 0

A scientist records the following sample of scores (n=6): 3,6,4,1,10,12. What is the sample mean of these scores?

M = 6.0

What is the formula for computing the range?

Max - Min

What is central tendency?

Measures of central tendency are statistical measures used to locate a single score that is most representative or descriptive of all scores in a distribution.

The mode is an appropriate measure for describing what types of data?

Modal distribution; qualitative, nominal data any type of data with a value that occurs the most, although it is typically used together with the mean or the median.

A researcher records the following time (in seconds) that children in a sample play with an unfamiliar toy: 12, 14, 10, 6, 8, 10, 13, 12, 4, 12, and 6. Which measure of central tendency (the mean, median, or mode) is largest? Choose one mean median mode all measures for central tendency are equal

Mode

The _________ is the value in a data set that occurs most often or most frequently.

Mode

_____ symbolizes the size of a population, whereas ______ symbolizes the size of a sample.

N; n

A researcher reports that participants in her study had a mean age of 21.3 years with a range equal to 3. Based on this information, is it possible that one of the participants was 25 years old in her study?

No b/c the range is too small

17) Can a sample be larger than the population from which it was selected?

No because a sample is only a part of the population.

Researchers tested an index to discriminate between conscientious and random responders to surveys. As part of their study, they had participants complete the Conscientious Responders Scale (CRS). The mean score for the conscientious responders was 4.58 and the standard deviation was 1.16. Assuming the data are normally distributed in this example, would a score above 5.0 be unlikely? Explain.

No, a score of 5 would be likely. It falls within 1 standard deviation of the mean and therefore is likely to occur.

A researcher measures the following scores: 0, 2, 2, 2, 2, 2, 4, 4, 4, 4, 0, 0, 0, 0, 0, 0, 0, 2, 2, 2, 2, 2, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 0, 2, 4, 2, 2, 4, 4, 4, 4, 4, and 0. Should these data be grouped? yes, because so many scores were measured yes, because the range of values is small no, because the data are categorical no, because the number of different scores is small

No, because the number of different scores is small

A student computes a variance of 9. Will the standard deviation differ if 9 is the value for a population versus a sample difference? Explain.

No, in both cases, the standard deviation is the square root of the variance. Hence, the population and the sample standard deviation will be the sqrt (9) = 3.0.

13) A researcher measured behavior among all individuals in a small population. Are inferential statistics necessary to draw conclusions concerning this population? Explain.

No, it's not. Inferential statistics are used in situations where the population is too large to draw information or observe everyone in the population. In a small population such as this one, they do not need to infer or generalize observations, because the researcher has the ability to observe first hand the entire population.

Scientists investigated perceived wellness among freshmen military cadets at the Citadel academy. Cadets completed the Five Factor Wellness Inventory to measure their perceived wellness pertaining to creative, coping, social, essential, and physical wellness. Total wellness scores ranged from 14.84 to 71.60, with 50.00 +/-9.99. Are these data approximately normally distributed? Explain.

No, the data are likely skewed because the mean is pulled toward the larger scores in the distribution.

22) Rank the scales of measurement in order from least informative to most informative.

Nominal, ordinal, interval, ratio

The empirical rule is stated for data with what type of distribution?

Normal distribution

The mean is an appropriate measure for describing what types of data?

Normal distribution; interval and ratio scaled data (quantitative)

What term is often used to describe behavior that falls within 2 SD of the mean in a normal distribution?

Normal or statistical norm

Scientists were interested in understanding how to characterize and study curiosity in children. In their article, they note "Although curiosity is an undeniably important aspect of children's cognitive development, a universally accepted (way of measure) curiosity does not exist." What type of definition according to these authors is needed for the term curiosity?

Operational definition

A ______ is a cumulative percent summary in which the ranks indicate the percentage of scores at or below a given value. relative percent percentile rank relative frequency cumulative frequency

Percentile rank

A graphical display in the shape of a circle that is used to summarize the relative percent of discrete and categorical data into sectors is called a ______. bar chart flow chart pie chart flow chart

Pie chart

9) A qualitative variable varies by ___________; a quantitative variable varies by __________.

Qualitative = class Quantitative = amount

Frequency data are not always distributed in intervals. What types of data are not distributed in intervals?

Qualitative or categorical variables and ungrouped data with few scores

A researcher is interested in the effects of stuttering on social behavior in children. He records the number of peers a child speaks to during a typical school day. In this example, would the data be qualitative or quantitative?

Quantitative

Temperature (Degrees F)

Quantitative; continuous; interval

Time (in minutes) to prepare dinner

Quantitative; continuous; ratio

Position standing in line

Quantitative; discrete; ordinal

A researcher conducts a study that includes a quasi-independent variable and lacks a comparison group. What type of research method is described? Choose one experimental method quasi-experimental method counterintuitive method investigative method

Quasi-experimental method

A school administrator has students rate the quality of their education on a scale from 1 (poor) to 7 (exceptional). She claims that 99.7% of students rated the quality of their education between 3.5 and 6.5. If the mean rating is 5.0, then what is the standard deviation, assuming the data are normally distributed?

SD = 0.5 5-3.5 = 1.5 (3 standard deviations away since 99.7% so divide 1.5 by 3)

A social psychologist records the age (in years) that a sample of eight participants first experienced peer pressure. The recorded ages for the participants are 14, 20, 17, 16, 12, 16, 15, and 16. Compute the SS, the variance, and the standard deviation for this sample.

SS = 37.5 s^2 = 5.36 s = 2.31

A researcher measures the following scores: 12, 14, 16, 18, and 20. Compute the SS for these data.

SS = 40

How is the formula for the sample variance different from the formula for the population variance? Choose one SS is computed without squaring the deviations of scores from the mean the value for SS is placed in the denominator of the sample variance formula SS is divided by the degrees of freedom for sample variance in the denominator of the formula for sample variance none; both formulas are computed the same

SS is divided by the degrees of freedom for sample variance in the denominator of the formula for sample variance

Describe the sum of squares (SS) in words

SS is the sum of the squared deviations of scores from their mean

State four characteristics of the standard deviation

The STD is always positive it is used to describe quantitative variables it is most informative when reported with the mean it is affected by the value of every score in a distribution

What does the standard deviation measure?

The average distance that scores deviate from their mean

A researcher asks children to choose which type of cereal they prefer (one with a toy inside or one without) He records the choice of cereal for each chid.

The choice of cereal is discrete and qualitative

How does calculating the sample variance differ from calculating the population variance?

The denominator for sample variance is (n-1) not N.

The standard deviation is a measure used to determine the average distance that each score deviates from __________.

The mean

The calculation of a population mean and sample mean is the same. State in words how to compute the mean.

The mean is the sum of a set of scores, divided by the total number of scores summed.

A group of researchers measures the weight of 5 participants prior to a clinical weight loss intervention. They record the following weights (in pounds): 200, 250, 150, 100, and 300 pounds. The mean is 200 pounds. Instead, the researchers reweigh the 300 pound individual and record a new weight of 350 pounds. Will the mean increase or decrease in this situation?

The mean will increase

A colleague measures the following heights (in inches) of 10 CEOs selected at random: 72, 75, 75, 66, 64, 79, 79, 75, 70, and 72. Which measure of central tendency is most appropriate for describing these data?

The median because the data are negatively skewed

Hilari and Northcott (2006) used a Social Support Survey (SSS) to gauge how well supported individuals suffering from stroke-induced aphasia (a language disorder) felt more than 1 year following the stroke. They reported that "in terms of social support, the SSS scores were negatively skewed with a mean of 3.69, suggesting that participants felt overall well supported". Based on their findings, what additional measure of central tendency would be appropriate to report with these data? Explain.

The median because these data are negatively skewed.

Patten and colleagues (2008) stated that "among nonsmokers who indicated they were close to a smoker whom they thought should quit, Black (participants) were most often concerned about a family member whereas White (participants) endorsed concern most often for a friend". What are the most common concerns (or mode) for each race?

The mode for nonsmoking Black participants was concern about a family member; the mode for nonsmoking White participants was concern for a friend

A researcher records the months of birth among patients with schizophrenia.

The month of birth is discrete, and qualitative

A professor records the number of students absent during a final exam.

The number of students is discrete and quantitative

A psychologist measures a sample of scores on a love quiz, where SD = 4 points. State the new value for SD if the psychologist (a) adds 2 points to each quiz score and (b) doubles each quiz score.

a) SD = 4 points b) SD = 8 points

Suppose that you sum the squared differences of scores from their mean. What is always true about the result you obtain?

The result is the smallest possible positive solution. Substituting any constant (other than the mean) will produce a larger result.

Although different symbols are used to represent the number of scores in a sample and population, the computation of central tendency is ______ for samples and populations. Choose one different the same minimal summed

The same

An instructor measures the following quiz scores: 6, 8, 7 and 9 (SD = 1.29). If the instructor subtracts 2 points from each quiz score, how will the value for the standard deviation change?

The standard deviation will not change (SD = 1.29)

14) Appropriately use the terms sample and population to describe the following statement: A statistics class has 25 students enrolled, but only 23 students attended class.

The statistics class has a population of 25 students enrolled, but a sample of only 23 students attended.

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 other who took the exam

State the characteristic of the mean that indicates that the mean is the "zero point" for a distribution of scores.

The sum of the differences of scores from their mean is zero

What does it mean to say that the sample variance is unbiased?

The variance of the sample will equal the variance of the population from which the sample was selected, on average

A researcher observes the following data set: 3, 5,4,4,6,7,8,2,3,2,4,2,2 and 4

There are two modes: 2 and 4 each occur four times

To investigate studying behavior among college students, a researcher measures the following variables: the duration of study time (in minutes per week), the number of breaks a student takes during a study session, and the time of day of studying (morning, afternoon, or night). Which is not a ratio scale of measurement? Choose one duration of study time number of breaks taken time of day of studying both B and C

Time of day studying

The upper boundary and of one interval and the lower boundary of the next interval do not overlap in a simple frequency distribution. Why?

To ensure that a single score does not get counted in more than one interval

T/F: A pictogram is an effective way to summarize frequency data

True

T/F: A ratio scale variable can be continuous or discrete

True

T/F: The sample variance is unbiased when dividing SS by (n-1)

True

T/F: When all scores in a population are the same, the variance will always be equal to 0.

True

T/F: Whether you cumulate a frequency distribution form the bottom up or the top down depends on how you want to discuss the data

True

T/F: A scientist measures the following data: 23, 23, 23, 23, 23, and 23. The value for the sample variance and population variance will be the same.

True because the variance is 0.

T/F: A researcher observes that a single parent works 42.25 hours per week. The degree of accuracy of 42.25 is to the hundredths place (.01)

True``

Disadvantage of measuring qualitative data? Why is quantitative better?

Usually fewer people studied: collection of qualitative data is generally more time consuming that quantitative data collection and therefore unless time, staff and budget allows it is generally necessary to include a smaller sample size. Quantitative research usually has more respondents than qualitative research because it is easier to conduct a multiple-choice survey than a series of interviews or focus groups.

_________ is a measure of the dispersion or spread of scores in a distribution and ranges from 0 to +infinity

Variability

State whether each of the following describes a study measuring a qualitative or quantitative variable: a) A researcher distributes open-ended questions to participants asking how they feel when they are in love. b) A researcher records the blood pressure of participants during a task meant to induce stress c) A psychologist interested in drug addiction injects rats with an attention-inducing drug and then measures the rate of lever pressing d) A witness to a crime gives a description of the suspect to the police.

a) Qualitative b) Quantitative c) Quantitative d) Qualitative

Why do we square each deviation in the numerator of variance?

We want to compute how far scores are from their mean without ending up with a solution equal to zero every time, and taking the square root of variance can correct for squaring each deviation in the numerator

When is it appropriate to summarize frequencies for ungrouped data?

When data sets have only a few different scores and for qualitative or categorical variables

Identify the mode: A study reports that women are more likely to ask for directions than men.

Women

Bauer et al. (2011) identified the median income of a middle-class family in their sample to be $84,200 annually; the mean family income was $85,300 annually. In their data, the lowest family income reported in this group was $65,100 annually, and the highest family income reported was $103,400 annually. Based on the data given, was the mean an appropriate value to summarize these data? Explain.

Yes, the mean would be appropriate because the data are approximately normally distributed (the mean and median do not differ greatly).

7) Can a nominal variable be numeric? Explain

Yes. They can be numbers that identify locations, vehicles, or individuals and nothing more.

A sample of 26 patients with major depressive disorder (MDD) showed an average of five symptoms of the disorder prior to diagnosis. What is the sum of differences of scores from the mean in this example?

Zero

Observational definition:

a description of some observable event in terms of the specific process or manner by which it was observed or measured

A set of data is normally distributed with a mean equal to 10 and a standard deviation equal to 3. Compute a z transformation for each of the following scores in this normal distribution: a) -2 b) 10 c) 3 d) 16 e) 0

a) -4 b) 0 c) -2.33 d) 2 e) -3.33

Identify the column in the unit normal table for each of the following: a) z-scores b) The area from each z score toward the tail c) the area between each z score and the mean

a) Column A b) Column C c) Column B

State whether each of the following is continuous or discrete: a) Delay (in seconds) it takes drivers to make a left-hand turn when a light turns green b) Number of questions that participants ask during a research study c) Type of drug use (none, infrequent, moderate or frequent) d) Season of birth (spring/fall/winter/summer)

a) Continuous b) Discrete c) Discrete d) Discrete

Pope conducted a study to test if noise levels measured in decibels differed in medical/surgical nursing units compared to patient rooms. She found that noise levels were substantially higher in the patient rooms compared to the nursing units. In this study, state whether noise levels in decibels were each of the following: a) continuous/discrete b) qualitative/quantitative c) nominal/ordinal/interval/ratio scale

a) Continuous b) Quantitative c) ratio scale

State whether each of the following is an example of continuous or discrete variable: a) time in seconds to memorize a list of words b) Number of students in a stats class c) weight in pounds of newborn infants d) SAT scores among college students

a) Continuous b) discrete c) continuous d) discrete

5) In an experiment, researchers measure two types of variavles: independent and dependent variables. (a) which variable is measured in each group? (b) which variable is manipulated to create the groups?

a) DV b) IV

If the value of the SS remains constant, state whether each of the following will increase, decrease, or have no effect on the sample variance. a) The sample size increases b) The degrees of freedom decrease c) The size of the population increases

a) Decrease b) increase c) no effect on the sample variance

11) State whether each of the following words best describes descriptive or inferential statistics. a) summarize b) infer c) describe

a) Descriptive b) inferential c) descriptive

12) State Whether each of the following is true or false: a) graphs, tables and summary statistics all illustrate the application of inferential statistics b) Inferential statistics are procedures used to make inferences about a population, given only a limited amount of data c) Descriptive statistics can be used to describe populations and samples of data

a) False b) True c) True

An instructor gives students a surprise quiz and records a mean grade of 12 points. What is the new mean value if the instructor does each of the following? a) Adds 10 points to each quiz b) Subtracts 2 points from each quiz c) doubles each quiz score d) divides each quiz score in half

a) Mean = 22 b) Mean = 10 c) Mean = 24 d) Mean = 6

What value represents: a) The midpoint of a distribution? b) The balance point of a distribution? c) The zero point of a distribution?

a) Median (always the middle of a distribution) b) Mean (all scores are included in its calculation; its value is most reflective of all the data) c) Mean because sum of the differences of scores from their mean is zero

State the statistical notation for each of the following terms: a) population size b) Sample size c) population mean d) sample mean

a) N b) n c) mew d) M

18) State whether each of the following variables is an example of an independent variable or a quasi-independent variable. a) Marital Status b) Political affiliation c) Time of delay prior to recall d) environment of research setting e) years of education f) type of feedback (negative/positive)

a) Quasi IV b) Quasi IV c) IV d) IV e) quasi IV f) IV

21) Researchers are interested in studying whether personality is related to the month in which someone was born. a) Is it appropriate to code the data? Explain. b) What scale of measurement is the month of birth?

a) Yes; The months should be coded from 0 to 12 in their natural sequence of occurrence, to carry on with numerical operations. b) Nominal

Scientists studied a possible link between smoking and certain personality traits by gender. In a description of their participants (M +/- SD), the researchers stated that "of those who reported smoking, men (n=61) and women (n=93) reported.... similar daily cigarette consumption per day (men: 4.25 +/- 6.25 cigarettes per day; women: 3.84 +/- 5.26 cigarettes per day)" a) State the degrees of freedom for variance for men and for women b) Assume these data are approximately normally distributed. Is it more likely that men or women smoked at least half a pack (10 cigarettes) per day? Explain.

a) dF men = 60 dF women = 92 b) Men are more likely to smoke at least half a pack per day because 10 cigarettes is within 1 SD of the mean for men but greater than 1 SD from the mean for women.

20) A researcher tests whether cocaine use increases impulsive behavior in a sample of cocaine-dependent and cocaine-inexperienced mice. a) identify the IV b) identify the DV

a) the cocaine use b) impulsive behavior

The mean is used to describe ______. Choose one data that are normally distributed interval scale data ratio scale data all of these

all of these

The median is ______. Choose one the preferred measure of central tendency when outliers are in a data set the middle value in a distribution listed in numerical order at the 50th percentile of a cumulative percent distribution all of these

all of these

When cumulating frequencies from the bottom up, you typically want to discuss the data in terms of: a) "at most" b) "Less than" c) "At or below" d) all the above

all the above

When cumulating frequencies from the top down, you typically want to discuss the data in terms of: a) less than b) at or above c) at most d) all of the above

b) at or above or greater than

The sample variance is an unbiased estimator of the population variance when we ______. Choose one divide SS by (n − 1) divide SS by df divide SS by N both A and B

both A and B

All of the following are rules for constructing histograms except: a) A vertical rectangle represents each interval, and the height of the rectangle equals the frequency recorded for each intervla b) The base of each rectangle begins and ends at the upper and lower boundaries of each interval c) each rectangle represents the frequency of all scores in a distribution d) each rectangle touches adjacent rectangles at the boundaries of each interval

c

Each of the following is a characteristic of standard deviation, except: a) The standard deviation is always positive b) The standard deviation is affected by the value of every score in the distribution c) The standard deviation is used to describe qualitative variables d) standard deviations are almost always reported with the mean

c

The size of a reward (in grams)

continuous; quantitative; ratio

When we sum the frequencies across a series of intervals, the summary is called a ______. simple frequency distribution cumulative frequency distribution relative frequency distribution cumulative percent distribution

cumulative frequency distribution

Each of the following is a rule for the simple frequency distribution except: a) Each interval is equidistant b) the same score cannot occur more than one interval c) each interval is defined (it has a lower and upper boundary) d) the interval width is equal to the number of intervals in a frequency distribution

d

The two general types of statistics are ______ and ______. Choose one summary; descriptive descriptive; inferential interpretive; analytical simple; complex

descriptive and inferential

Ratings of satisfaction (1 to 7)

discrete; quantitative; interval

ranking of favorite foods

discrete; quantitative; ordinal

Number of lever presses per minute

discrete; quantitative; ratio

A bar chart is similar to a histogram, except that in a bar chart, each rectangle ________ the adjacent rectangles at the boundaries of each interval. touches does not touch overlaps with none of these

does not touch

A researcher measures a sample mean for five samples. The sample mean in each sample is M = 2, M = 4, M = 5, M = 7, and M = 9. What will the sum of the differences of scores from the mean equal in each sample? Choose one minimal equal to 0 larger as the mean in the sample gets larger not enough information because the actual scores in each sample are not given

equal to 0

It is necessary to create intervals for a simple frequency distribution with what type of data? grouped data ungrouped data categorical data nominal scale data

grouped data

What is the key distinction between grouped and ungrouped data?

grouped data is distributed in intervals, ungrouped is not

A researcher measures the distance (in miles) that students travel during a holiday season. What type of graph (shown below) was used to summarize these data? Is it appropriate? histogram; yes, because the data are continuous histogram; yes, because the data are discrete histogram; no, because the data are continuous bar chart; yes, because the data are discrete

histogram; yes, because the data are continuous

Complete the following sentence: The normal distribution is used to determine the probability of a certain outcome ________ to all other outcomes.

in relation

A researcher measures a range equal to 12. What will the value of the interquartile range be for these same data? Choose one equal to the range greater than the range less than the range

less than the range

A professor is interested in studying the attitudes of students in her class. She has all of the students in her class fill out a survey and records their responses. In this example, the professor ______. Choose one failed to identify the population of interest measured data in the sample of students measured data in the population of students did not have enough data to draw conclusions about the population of interest

measured data in the population of students

Frequency polygons are plotted at the ________ of each interval, whereas ogives are plotted at the _______ of each interval

midpoint; upper boundary

A relative percent distribution is often used instead of a relative frequency distribution because ______. it is more appropriate it is more accurate it is more meaningful most readers find it easier to understand percentages than decimals

most readers find it easier to understand percentages than decimals

The mode is the primary measure of central tendency to describe data on which scale of measurement? Choose one nominal ordinal interval ratio

nominal

State the scales of measurement from least to most informative: Choose one ratio, interval, ordinal, nominal nominal, ordinal, interval, ratio ordinal, interval, nominal, ratio nominal, ratio, ordinal, interval

nominal, ordinal, interval, ratio

The standard deviation is most informative for describing what type of distribution? Choose one normal distribution skewed distribution bimodal distribution nonmodal distribution

normal distribution

The mean is the balance point of a distribution, which means that it is ______. Choose one always equal to 0 not always located at the center of a distribution of scores equal to the score in the middle of a distribution of scores used to measure the extent to which objects balance

not always located at the center of a distribution of scores

A characteristic in a population is called a ______, whereas a characteristic in a sample is called a ______. Choose one population parameter; sample statistic sample statistic; population parameter sample parameter; population statistic population statistic; sample parameter

population parameter; sample statistic

The ______ is the square root of the ______. Choose one range; interquartile range mean; median variance; standard deviation standard deviation; variance

standard deviation; variance

A _____________ is a summary that display that uses symbols or illustrations to represent a concept, object, place, or event

pictogram

The _______ is the sum of N scores divided by N, whereas the ______ is the sum of n scores divided by n. population mean; sample mean sample mean; population mean

population mean; sample mean

A researcher records the family relationship (brother, son, father, cousin, etc.) of the people who stay in regular contact with loved ones in a nursing home. What type of measure is family relationship? Choose one quantitative and discrete qualitative and discrete qualitative and continuous quantitative and continuous

qualitative and discrete

Sex

qualitative; discrete; nominal

seasons

qualitative; discrete; nominal

Time of day

quantitative; continuous; ratio

Rating scale score

quantitative; discrete, interval

Movie ratings (1 to 4)

quantitative; discrete; ordinal

Number of students in your class

quantitative; discrete; ratio

A researcher places a participant in a room filled with 10 strangers. To measure social behavior, he records the number of different people the participant talks to and the time (in seconds) spent talking. The number of people the participant talks to is a ______ variable; the time (in seconds) spent talking is a ______ variable. Choose one quantitative; qualitative qualitative; quantitative qualitative; qualitative quantitative; quantitative

quantitative; quantitative

A researcher measures the number of hours spent studying among students living on campus and off campus at a local college. In this study, location (on campus, off campus) is the ______ and hours spent studying is the ______. Choose one independent variable; dependent variable dependent variable; independent variable quasi-independent variable; dependent variable dependent variable; quasi-independent variable

quasi-independent variable; dependent variable

A ______ frequency distribution is often used for larger data sets where the number of frequencies in each interval could be in the thousands or millions. simple cumulative relative differential

relative

A researcher measures the following data: 3, 3, 3, 4, 4, and 4. What is the sample variance for these data?

s^2 = 0.3

A sample of 60 scores is distributed with an SS = 240. What is the sample variance and sample standard deviation for this distribution?

s^2 = 4.07 Standard deviation = 2.02

The sum of the deviation of scores from their mean is zero. To avoid this result, each deviation is ______. Choose one summed squared divided multiplied

squared

The mean for a distribution of scores is M = 6. If we measure a new score equal to 10, then what will happen to the mean? Choose one the mean will increase the mean will decrease the mean will remain the same

the mean will increase

Which of the following describes the calculation for the sum of squares (SS) using the definitional formula? Choose one the sum of the deviations of scores from the mean the sum of the squared deviations of scores from the mean the average distance that scores deviate from the mean the average distance that scores deviate from each other

the sum of the squared deviations of scores from the mean

The sample variance is a(n) ______ when, on average, its value is equal to the value of the population variance. biased estimator unbiased estimator

unbiased estimator

what are the data called when the frequency of each individual score or category is listed?

ungrouped data