Student Created Midterm Study Guide (in class)
If the Xi value is approximately one standard deviation below the mean, what is its z-score? a. +1.96 b. +1 c. -1.96 d. -1
-1
Which is NOT a possible value for "r" (correlation)? a. -0.89 b. 0.42 c. 0.00 d. -1.1
-1.1
What values can R-squared take on, and which of these values represents a perfectly linear relationship? a. -1 to 1; 0 b. -1 to 1; 1 c. 0 to 1; 1 d. -1 to 0; 0
0 to 1; 1
The mean of a standardized normal curve is ________ and the standard deviation is ______. a. 0, 1 b. 1, 0 c. 0.05, 1 d. 1, 1
0, 1
You have a set of data containing the favorite colors of a sample. What type of data is this, and what type of visual representation would be best suited to showcase the results? a. interval, histogram b. nominal, histrogram c. interval, pie chart d. nominal, pie chart
nominal, pie chart
When choosing to visually represent your data, what should you consider? a. scales you are using b. audience c. interval size d. all of the above
all of the above
In which of the following scenarios would it be appropriate to create and analyze a linear regression? a. analyzing the relationship between shoe size and height b. analyzing the significance of population standard deviation c. analyzing the relationship between nominal variables d. analyzing the relative strength of the relationship
analyzing the relationship between shoe size and height
If we fail to reject the null hypothesis a. any difference found was not likely due to chance b. any difference found was likely due to chance c. any difference found was proved d. any difference found was not proved
any difference found was likely due to chance
Which of the following does percentile represent? a. area under a normally distributed curve b. the percent of data that is valid c. the difference between the lowest and highest values in your dataset d. none of o the above
area under a normally distributed curve
People filled out a questionnaire asking their sex and their level of education, which way is preferred to visually represent the data? a. bar graph b. pie chart c. scatter plot d. both a and b
both a and b
What do z-scores tell us? a. what percentile a score falls in b. results likely due to chance c. how extreme the difference is d. both a and b
both a and b
What does R-squared tell you? a. how accurate of a predictor the independent variable is for the dependent variable b. the strength and direction of the relationship between the two variables c. both a and b d. none of the above
both a and b
What does a small standard deviation tell us? a. the data is more reliable b. low variability c. values in the data set are farther away from the mean d. both a and b
both a and be
What best describes a mesokurtic curve? a. less variable b. flat c. normal distribution, bell shaped d. linear e. none of the above
normal distribution, bell shaped
Based on the graph, which of the following is the correct order? a. mode, mean, median b. mean, mode, median c. mean, median, mode d. median, mode, mean
mean, median, mode
On a negatively skewed graph, what order do mean, median, and mode come in (left to right)? a. mode, mean, median b. median, mode, mean c. mean, mode, median d. mean, median, mode
mean, median, mode
What type of central tendency is best used to describe a positively skewed graph? a. mode b. median c. variance d. all of the above
median
When there is a skew in the distribution of data in a sample due to outliers, which measure of central tendency should be used? a. mean b. median c. mode
median
Which of the following central tendencies would MOST LIKELY be used to represent household incomes with possible outliers? a. mode b. mean c. median d. all of the above
median
In the regression equation for two variables, r = 0.3, then how strong is the relationship for these two variables? a. weak b. medium c.strong
medium
What is the purpose of the line of best fit? a. To make our graph aesthetically pleasing b. Determines the significance of the slope c. Minimizes the difference between Y-hat (predicted Y) and actual Y (observed Y) d. Gives us our "r" value
minimize the difference between y-hat and actual y
What measure of central tendency is best to use when considering nominal data? a. median b. mean c. mode
mode
What measure of central tendency measures the most frequent response? a. mean b. median c. mode d. standard deviation
mode
Which of these is NOT a type of variability? a. standard deviation b. range c. mode d. variance
mode
For positive skew, what order does the mean, median, and mode go in? a. mode, median, mean b. mean, median, mode c. mode, mean, median d. median, mode, mean
mode, median, mean
If a distribution was described as having a negative skew, what type of outliers would it have? a. more negative outliers b. more positive outliers c. no outliers d. both strong positive and strong negative outliers
more positive outliers
We did a z-test to see if a new drug can treat high blood pressure. We got a p-value of 0.032, and then we rejected the null hypothesis. What type of error have we made? a. Type I b. Type II c. no error was made d. not enough information
no error was made
Which type of scale has no numerical significance? a. nominal b. ordinal c. interval d. ratio
nominal
What is the slope in the regression equation? a. b b. unstandardized regression coefficient c. a linear relationship d. all of the above
all of the above
What is the main form of central tendency we are interested in for a z-test? a. mode b. median c. mean d. range
mean
What p-value is required in order to reject the null hypothesis? a. 0 b. 0.5 c. 0.05 d 1
0.05
What R-squared value would predict a strong relationship between the line of best fit and the data? a. 0.1 b. 0.07 c. 0.25 d. 20.8
0.25
How many degrees of freedom are lost when performing a t-test for independent groups? a. 0 b. 1 c. 2 d. we do not have enough information
2
What does 25th percentile mean?
25% of scores fall below your scores
How do you apply the value of a 3.10 GPA into the percentile formula? a. 3.10 is the P value in the formula b. 3.10 is the X value in the formula c. 3.10 is the N in the formula d. 3.10 is the i value in the formula
3.10 is the X value in the formula
Candice scored in the 70th percentile of her class on a midterm. What percentage of the class scored better than her? a. 70% b. 30% c. 69% d. 29%
30%
What percentile does the median value represent? a. 25th b. 33rd c. 50th d. 68th
50th
Two standard deviations away from the mean in a normal distribution would cover _______ percent of the data. a. 68 b. 95 c. 99.7 d. 100
95
In a distribution of high school GPAs (sub0.34) was determined to be 3.25. What is the most accurate interpretation of this descriptor? a. 66% of high schoolers included in this distribution have a GPA below 3.25 b. a GPA of 3.25 is the point below at which 34% of GPAs fall c. 34% of high schoolers included in this distribution have a GPA above 3.25 d. a GPA of 3.25 is the point above which 34% of GPAs fall.
A GPA of 3.25 is the point below at which 34% of GPAs fall
A high school student receives an SAT score of 1450 and an ACT score of 32. Which score should this student submit to their desired colleges and why? a. SAT because a score of 1450 means 90th percentile b. ACT because a score of 32 means 92nd percentile c. SAT because a score of 1450 means 10th percentile d. not of the choices are better than the other
ACT because a score of 32 means 92nd percentile
You're running an analysis of data on SPSS. As you increase the sample size, you notice that the distribution appears to be more normal. What theory is this demonstrating? a. standard error of mean b. theorem of standard deviation c. t-test theory d. Central Limit Theorem
Central Limit Theorem
What is the difference between descriptive and inferential statistics? a. Descriptive statistics describe aspects of a sample. Inferential statistics draw inferences about the population where the sample was drawn. b. inferential statistics describe aspects of a sample. Descriptive statistics draw inferences about the population where the sample was drawn. c. Descriptive statistics test the significance. Inferential statistics are always helpful. d. Descriptive statistics are not a thing. Inferential statistics are always helpful.
Descriptive statistics describe aspects of a sample. Inferential statistics draw inferences about the population where the sample was drawn
T/F: A negative skew of data means there is more data on the negative side of the graph.
False
What is the difference between interval and ratio scales? a. Ratio scales have no true zeros, while interval has a true zero b. Interval does not have equidistant scales and no true zeros. Ratio has equidistant scales and a true zero. c. Interval has equidistant scales and no true zeros. Ratio has equidistant scales and a true zero. d. Ratio scales have no true zeros, while interval has true zero.
Interval has equidistant scales and no true zeros. Ratio has equidistant scales and a true zero.
T/F: An example of sampling distribution would be taking the average income from 30 sample groups of 25 in different age demographics in North Carolina to determine the average income of the whole state.
True
T/F: An independent variable does not depend on another variable, and a dependent variable depends on the other/independent variable
True
Which of the following is TRUE regarding errors? a. Type I error is a false negative and Type II error is false positive b. Type I error is false positive and Type II is false negative c. Type I error is false positive and Type II is false positive d. Type I error is false negative and Type II is false negative
Type I error is false positive and Type II error is false negative
A psychologist failed to reject the null hypothesis when it was false. What type of error is this? a. Type I b. Type II c. both Type I and Type II d. there is no error
Type II
How can you determine the score you would need to fall at the given percentile of GRE scores that the graduate programs require? a. calculate the median score of GRE scores from each respective school b. use the percentile formula to determine how your score compares c. observe the mean of all GRE scores nationwide d. calculate the standard deviation of GRE scores from each respective school
Use the percentile formula to determine how your score compares
Richard is conducting a two-tailed Z-test to determine if voter turnout in Chapel Hill is different from that of the rest of the state. His test yields a Z-score of -1.98, with a corresponding p = 0.0239. What can conclude? a. we can conclude that there is not a significant difference between voter turnout in Chapel Hill compared to the rest of North Carolina b. We can conclude that voter turnout in Chapel Hill is statistically greater than that of North Carolina as a whole c. We can conclude that there is a statistically significant chance voter turnout in Chapel Hill is lower than that of North Carolina as a whole d. We can conclude that voter turnout in Chapel Hill is statistically less than that of North Carolina as a whole
We can conclude that there is a statistically significant chance voter turnout in Chapel Hill is lower than that of North Carolina as a whole
What does a negative skew look like? a. a symmetrical graph b. a graph with a few outliers near the origin and most at larger X values c. a graph with few outliers at a large X value d. a graph with no values at zero
a graph with a few outliers near the origin and most at larger X values
What part of the regression equation remains constant? a. a b. b c. e d. Y
a
After running a Z-test, Timothy realized that he had made a type II error. Which of these analogies most closely describes a Type II error? a. a pregnancy test coming back positive when the woman is not pregnant b. a pregnancy test coming back negative when the woman is pregnant c. a pregnancy test coming back positive when the woman is pregnant d. a pregnancy test coming back negative when the woman is not pregnant
a pregnancy test coming back negative when the woman is actually pregnant
Select which data set would be best represented by a median? a. a skewed data set b. a data set with no outliers c. a data set with a normal distribution d. none of the above
a skewed data set
Which of the following case studies describes an inferential statistics study: a. a study using a sample of junior at UNC and a sample from Duke to compare mean GPA b. a study that focuses on the constant changes in a population that are continuous such as time and birth rate c. a study that draws conclusions that can be referred to as "educated guesses" based on the significance of differences between the samples d. none of the above
a study that draws conclusions that can be referred to as "educated guesses" based on the significance of the differences between the samples
A z-score can be used to a. calculate the percentile of a particular point b. compare scores across a distribution c. compare the sample to the population d. all of the above
all of the above
Explain the difference between variance and standard deviation. a. standard deviation is smaller than variance b. standard deviation is the square root of variance c. standard deviation looks at the spread of numbers in a data set compared to mean, while variance represents the average difference of all data points from a mean d. all of the above
all of the above
If we wanted to analyze ACT and SAT scores, which of the following is a step to compare these values? a. standardize the scores b. transform both X and Y into z-scores c. make the mean equal to 0 and the standard deviation equal to 1 d. all of the above
all of the above
What do statistics do? a. describe variables b. describe relationships c. describe number d. all of the above
all of the above
What does it mean if your value falls in the "critical region"? a. your value is below -1.96 or above 1.96 b. you value is statistically significant c. you reject the null hypothesis d. all of the above
all of the above
What does standardizing data to create a normal distribution allow us to... a. compare two samples to one another b. compare a sample to a parameter's population c. compare individuals from separate distributions d. all of the above
all of the above
What is the importance of random sampling? a. it eliminates bias b. it increases validity c. it is more representative of the entire population d. all of the above
all of the above
What does the Central Limit Theorem state? a. the sampling distribution is not normal distribution b. as sample size increases, the mean of the sample will be closer to the mean of the population c. sample will have the same range of as the population d. variance increases
as sample size increases, the mean of the sample will be closer to the mean of the population
What variable signifies slope in the linear regression equation? a. b b. m c. Xi d. A
b
Which of the following characteristics would make the measure scale a ratio scale: a. the scale has numbers that simply identify variables without any magnitude b. in the scale there is equal distance between the points c. there is a true zero point d. b and c e. a and c
b and c
Why is the mean the most commonly used form of central tendency? a. because the median is more heavily influenced by outliers b. because each point is weighed equally and it minimizes deviation c. because it works for nominal, ration, ordinal, and interval scales d. because it focuses on the most frequent responses
because each point is weighed equally and it minimizes deviation
In a study of SAT scores from the incoming class at a certain university, the mean is 1380 while the median is 1310. What does this suggest about the distribution of SAT scores? a. there are outliers on the higher end of the distribution b. the distribution is positively skewed c. the distribution is negatively skewed d. both a and b e. both a and c
both a and c
What the effect of adding the error term (ei) into the linear regression equation? a. changes the resulting y-value from a prediction to the actual outcome b. signifies that the resulting y-value of the modified equation isn't correct c. gives us some idea of the residual value for a data point d. both a and c
both a and c
Why is standard deviation typically used over variance? a. standard deviation puts the scores in raw units b. variance weighs outliers more heavily c. standard deviation and variance are both used equally d. both a and c
both a and c
When is a t-test used over a z-test? a. if the population standard deviation is unknown b. when the population standard deviation is known c. when we have a larger sample size d. when we have a smaller sample size e. both a and d
both a and d
The mean is incredibly useful and one of the most commonly used summary statistics. Which of the following is an issue regarding the mean? a. the mean has no flaws b. the mean only really makes sense with interval and ratio scales c. the mean is easily affected by outliers d. both b and c
both b and c
How do z-scores help us determine relative standing? a. are an indicator of correlation between two variables/data sets b. can be used to calculate percentile ranks and points c. are a measure of central tendency d. help indicate if our data is affected by Type-I or Type II errors
can be used to calculate percentile ranks and points
All of the following are types of distributions, EXCEPT: a. sample distribution b. sampling distribution c. population distribution d. central tendency
central tendency
Which of the following would represent inferential statistics? a. cumulative frequency b. central tendency c. kurtosis d. variables
central tendency
What do z-scores allows us to do that relative standing does not? a. predict the dependent variable based on the independent variable b. compare scores across distributions c. compare scores within the same population d. all of the above
compare scores across distributions
What is a t-test used for? a. comparing sample means b. determining statistical significance c. finding the mean d. determining the variability
comparing sample means
A sampling distribution is a distribution of a. distribution of scores of an entire population b. distribution of sample statistics c. distribution of scores of a sample from a population d. distribution of ranges
distribution of sample statistics
In which of the following cases would an independent samples t-test not be appropriate? a. comparing students' attitude change between the start and end of their degree b. comparing the attitudes of Eastern and Western individuals c. comparing the performance of individuals who either consumed caffeine or did not d. comparing aggression levels between one group who experiences high levels of excitation and one group who remained calm
comparing students' attitude change between the start and end of their degree
Time would be an example of which type of variable? a. discrete b. continuous c. categorical d. none of the above
continuous
You can increase power by a. decreasing sample size b. creating a more homogenous population c. increasing the standard error of mean d. having less degrees of freedom
creating a more homogenous population
One dataset has a range of 10, and another dataset has a range of 3. Assuming there are the same amount of data points for both sets of data, which dataset is likely to have a leptokurtic curve? a. dataset 10 b. dataset 3 c. none of them d. not enough information
dataset 3
Percentile rank can be used for: a. describing what a particular data point means in absolute terms to other data points b. describing what a particular data point means relative to other data points c. describing what a whole population means in absolute terms relative to other whole populations d. describing what a whole population means relative to other whole populations
describing what a particular data point means relative to other data points
Measures of frequency, central tendency, dispersion or variation, and position are all major types of what type of statistics? a. descriptive b. inferential c. analytical d. population
descriptive
I am testing to see whether a sample of individuals differ in height from another group. When I initially find the mean height of one sample, what type of statistics am I using? a. inferential statistics b. descriptive statistics c. power statistics d. regression analysis
descriptive statistics
The average weight of a group would be an example of? a. differential statistics b. descriptive statistics c. inferential statistics d. hypothesis testing
descriptive statistics
The percentile formula can be used to a. determine at what percentile a given score falls b. determine the score that would fall at a given percentile c. solve for N d. determine the number of cases falling below a given score
determine at what percentile a given score falls
What does hypothesis testing allow us to do? a. determine if there is a difference that is due to more than chance b. compare if the error is Type I or Type II c. explain power d. find the standard deviation
determine if there is a difference that is due to more than chance
A z-score allows us to do all of the follow, EXCEPT: a. determine percentile rank b. compare across different distributions c. determine the standard deviation of a number from the mean d. determine the direction of skewedness in a graph
determine the direction of skewedness in a graph
Which of the following is a way that relative standing is useful in everyday life? a. determining your GPA relative to others in your class b. determining if a difference in quiz scores is due to chance c. determining if each class member has an equal chance of being selected for a study d. determining if the sampling distribution is representative of the population
determining your GPA relative to others in your class
If we were to conduct a study on the impact of the number of children and life quality, what type of variable is the number of children? a. discrete b. nominal c. continuous d. descriptive
discrete
What is the difference between discrete and continuous variables? a. discrete there are a finite number of values, and continuous there are an infinite number of values b. continuous there are a finite number of values, and discrete there are an infinite number of values c. continuous and discrete are similar and both deal with values d. none of the above
discrete there are a finite number of values, continuous there are an infinite number of values
What is a sample statistic? a. the distribution of scores for an entire population b. it is the same as a sampling distribution c. distribution of scores in a particular sample d. a sample that is unreliable
distribution of scores in a particular sample
When we use histograms, what do we assume? a. there is nominal data b. each interval is equal c. this is the best way to present any data d. intervals are uneven
each interval is equal
In inferential statistics, "random samplings" assumes a. each member has an equal chance of being chosen b. each outcome has an equal chance of occurring c. each inferential statistic technique has an equal chance of people used d. each selection sampling technique has an equal chance of being used
each member has an equal chance of being chosen
What does the "e" stand for in the regression equation Y = bx + a + c? a. intercept b. slope c.error in the equation
error in the equation
If our z-statistic is between -1.96 and 1.96, what do we do with our null hypothesis? a. reject b. accept c. fail to reject d. retest it
fail to reject
What is a Type II error? a. Failing to reject the null hypothesis when it is true. b. Rejecting the null hypothesis when it is true. c. Rejecting the null hypothesis when it is false. d. Failing to reject the null hypothesis when it is false.
failing to reject the null hypothesis when it is false
A class interval allows for complicated data to be simplified in a more understandable way. Which of the following is the best example of a class interval? a. grade scale at school (A, B, C, D, F) b. temperature of the room c. speed limit on the highway d. the time of your first class on Mondays?
grade scale at schools (A, B, C, D, F)
When would you use a z-test? a. have a sample and want to learn about the population from which it was drawn b. have two samples and want to compare them to each other c. have two populations and want to compare them to each other d. have a population and want to see how many samples you can make
have a sample and want to learn about the population from which it was drawn
Which statement regarding histograms and bar graphs is true? a. both are used for continuous data b. both are used for nominal data c. histograms are used for continuous data, and bar graphs are used for discrete variables d. histograms are used for discrete variables, and bar graphs are used for continuous variables
histograms are used for continuous data, and bar graphs are used for discrete variables
How do histograms differ from bar graphs? a. histograms are generally for larger sample sizes b. bar graphs are used to show distributions of variables while histograms are used to compare variables c. they are the same d. histograms are used to show distributions where the intervals are the same for all of the variables, while bar graphs are used to compare variables
histograms are used to show distributions where the intervals are the same for all of the variables, while bar graphs are used to compare variables
When using independent samples t-test, it is assumed that the populations where samples are taken from display a. variance b. homogeneity of variance c. no variance d. inequality of variace
homogeneity of variance
In the context of an independent samples t-test, what does the t-statistic actually mean? a. how far away the means of the two groups are from each other b. how different the standard deviations of two groups are c. how big the differences are between two groups, when taking into account the differences within each group d. how big the differences are between a group and the overall population, when taking into account the differences within each group
how big the differences are between two groups when taking into account the differences within each group
Standard deviation is a. how reliable the mean is b. the distance of the data point from the mean c. how the data differs from the mean on average d. how reliable the data is in comparison to the mean
how the data differs from the mean
What does the t-test determine? a. if there is a significant difference between two groups' means b. if there is a significant difference between two groups' standard deviations c. what the mean of a population is given a sample's mean d. if the mean of a sample is useful
if there is a significant difference between two groups' means
In what scenario would you use a two tailed test? a. if you want to know if your GPA is above your class average b. if you want to know if your class average is different than the university average c. if you want to know if your test score is below your class average d. if you want to know if you are doing great in life
if you want to know if your class average is different than the university average
Which of the following is TRUE in regards to the null hypothesis? a. in a null hypothesis, differences are likely due to chance and there are significant differences b. in a null hypothesis, differences are not likely due to chance and there are significant differences c. in a null hypothesis, differences are likely due to chance and there are no significant differences d. in a null hypothesis, differences are not due to chance and there are no real differences
in a null hypothesis, differences are likely due to chance and there is no real difference
Which of the following is TRUE in regards to the alternate hypothesis? a. in an alternative hypothesis the differences are not likely due to chance and there are significant differences b. in an alternative hypothesis the differences are due to chance and there are significant differences c. in an alternative hypothesis the differences are not likely due to chance and there are not significant differences d. In an alternative hypothesis the differences are likely due to chance and there are not significant differences
in an alternative hypothesis, the differences are not likely due to chance and there are significant differences
Which is NOT a way to strengthen the relationship between two variables? a. standardize b. transform x and y into z scores c. means equal 0 d. increase participants in study
increase participants in study
According to the Central Limit Theorem, the sampling distribution of sample means from a population will approach normal distribution as the number of samples (N) in the sample distributio: a. decreases b. increases c. stays the same d. none of the above
increases
What is the difference between independent samples and correlated/paired samples t-test? a. independent is comparing one sample to a population; correlated samples are comparing two samples to a population b. independent is comparing two samples individually; correlated is comparing comparing a group c. independent samples only involve one person's data whereas correlated samples are two or more people's data d. They are the same
independent is comparing two samples individually; correlated is comparing comparing a group c. independent samples only
What type of test is most appropriate if you wanted to see if there was a significant difference between the GPAs of students involved in Greek life at UNC and at NC State? a. Regression and correlation analysis b. Correlated samples t-test c. Independent samples t-test d. T-test for correlations
independent samples t-test
With what type of statistics can you make generalizations about populations? a. descriptive b. inferential c. analytical d. population
inferential
You've been arguing with a business major about whether or not psychology students are shorter than the rest of the population for weeks, and you decide that you need to finally resolve the argument. You have the average height of a 182-person sample of psychology students and want to compare it to the population to prove him wrong. Unfortunately, you're unable to gather the population average, so you have to use data from a general population sample instead. What type of statistics would you use to resolve the argument? a. t-test b. descriptive c. nominal d. inferential
inferential
Z-testing and t-testing are part of what type of statistics? a. differential b. inferential c. descriptive d. hypothesis testing
inferential
If Dr. Harrison wanted to see if his section performed significantly better than another PSYC 210 section, he would use: a. descriptive statistics b. inferential statistics c. continuous statistics d. discrete statistics
inferential statistics
What kind of scale is usually a Likert scale? a. ordinal b. nominal c. ratio d. interval
interval
Which type of measurement would best interpret stress levels? a. nominal b. ordinal c. ratio d. interval
interval
Histograms are best used for which types of descriptive data? a. interval and ratio b. nominal and interval c. ratio and ordinal d. nominal and ordinal
interval and ratio
In PSYC 210, Dr. Harrison gave a pop quiz in which the lowest score was a 60 and the highest score was a 95, in what way is range relevant to this data? a. it allows you to calculate the mean of the data b. it allows you to see the lowest and highest scores in order to view the spread of the data c. it allows you to see how much your score deviates from the mean d. it's not relevant to this data
it allows you to see the lowest and highest scores in order to view the spread of the data
Why is multiple regression testing better than using a simple linear model? a. it can be use to understand relationships for many variables b. it is not a better predictor c. it includes a t-test that compares the means of the data d. it is more accurate
it can be used to understand relationships for many variables
What does variability explain? a. it is the maximum score minus the minimum score of a sample b. it describes the square root of the variance c. it describes the degree to which scores differ from each other d. it describes the equal chance each member in the population has of being chosen for sampling
it describes the degree to which scores differ from each other
What is one limitation of regression? a. it shows the best fit line for describing the relationship between two variables b. it does not show us the worst line for describing the relationship between two variables c. it does not tell us the relative strength of the relationship d. it allows us to compare relationships between variables
it does not tell us the relative strength of the relationship
When does the Type I error rate change? a. by improving your measurement b. it doesn't change c. by increasing your sample size d. by setting it to something else
it doesn't change
How do z-scores allow us to compare scores across different distributions? a. it equates the means by making them 0 and the variances by making them 1 b. it equates the means by making them 1 and the variances 0 c. it puts in a non-normal distribution d. z-scores are not the values used to do this
it equates the means by making them 0 and the variances by making them 1
Which of the following is not a characteristic of a normal distribution? a. the mean is equal to 0 b. it is asymptotic c. the curve is symmetrical d. it is a discrete distribution
it is a discrete distribution
What does the slope mean in regression equation? a. it is the linear relationship between two variables b. X and Y c. it correlates with many y-intercepts d. the strength of the line
it is the linear relationship between two variables
What does the term "variable" mean in reference to statistics? a. label given to a concept that can differ between individual people b. data that can change depending on the type of population c. a use of measurement in psychological d. a way to code human behavior
label given to a concept that can differ between individual people
What type of kurtosis describes a graph that is taller and thinner than a normal distribution? a. platykurtic b. leptokurtic c. mesokurtic d. normal
leptokurtic
In a z-test, your data is considered statistically significant when the p-value is _______ the critical value (0.05)? a. greater than b. less than c. equal to d. none of the above
less than
Given the z-score, x-value, and standard deviation, what value can you solve for? a. mode b. median c. mean d. standard error
mean
In a statistical graph that is negatively skewed, which measure of central tendency is most susceptible to the rest? a. mode b. median c. mean d. range
mean
Oh no! You tripped over a basketball while rushing Franklin Street after a Duke game, and now you are at Urgent Care to get your leg checked out. The nurse asks you to rate your pain on a scale from 1-10. Which type of scale does this exemplify? a. ratio b. nominal c. ordinal d. interval
ordinal
What type of scale would best be represented by a 1 to 10 scale on how stressed students are at a given time? a. nominal b. ordinal c. ratio d. interval
ordinal
What describes what a particular data point means relative to other data points? a. Data Transformation b. t-test c. z-score d. percentile rank
percentile rank
What is relative standing most closely related with? a. skewness b. percentile rank c. variability d. standard error of mean
percentile rank
What do we use z-scores to calculate? a. t-test b. scatter plots c. percentile ranks and points d. correlation
percentile ranks and points
What type of graph is best for nominal data? a. histogram b. bar graph c. pie chart d. line graph
pie chart
Which type of kurtosis displays wider variability? a. mesokurtic b. platykurtic c. leptokurtic d. none of the above
platykurtic
A researcher wants to study all of the students taking PSYC 210 at UNC. This would be what kind of distribution? a. sample b. sampling c. population d. random
population
If Tommy were to record the heights of all the students in his class and graphed his data, this would be considered a: a. sample distribution b. population distribution c. distribution of sampling d. distribution of means
population distribution
Emma received an 84 on her math exam. She feels like she has done well but she wants to know how she did in comparison to her class. If her percentile is 62% in comparison to her class is her z-score positive or negative? a. negative b. positive c. there is not enough information to tell
positive
How can the skew of the graph be best described? a. postive b. negative c. normal d. none of the above
positive
How does the Central Limit Theorem apply to z-tests? a. shows exactly what the population is b. it doesn't c. provides a general expectation of the proposed population mean and standard deviation in order to determine which sample means would be too different from the population d. provides a general expectation of the proposed population mean and standard deviation in order to determine which sample means would be too similar from the population
provides a general expectation of the proposed population mean and standard deviation in order to determine which sample means would be too different from the population
Relative standing... a. puts descriptive statistics into context and comparison b. is the square root of average square deviation from the mean c. is the same as z-score d. is the maximum score minus the minimum score
puts descriptive statistics into context and comparison
Which of the following is NOT a measure of central tendency? a. mode b. range c. median d. mean
range
Your teacher gives you your exam back and you got an 80. You know that the average on the exam was an 85. What measure of variability would tell you how your score compares to the whole class? a. standard deviation b. variance c. range d. mean
range
A histogram will be most useful/accurate in displaying data for which type of scale? a. nominal b. ordinal c. interval d. ratio
ratio
What type of scale would you use to measure letter grades in a class? a. interval b. nominal c. ratio d. ordinal
ratio
What type of scale would you use if you wanted to measure the ages of US Olympic athletes? a. nominal and discrete b. ordinal and discrete c. interval and continuous d. ratio and continuous
ratio and continuous
Which of the following scales world best when using the mean? a. ratio and interval b. nominal c. ordinal d. all of the above
ratio and interval
How can the power (1-beta) be increased? a. having a mean of 0 and a standard deviation of 1 b. reducing error variance and increasing sample size c. having an alpha more than .05 d. by failing to reject the null hypothesis
reducing error variance and increasing sample size
What is a Type I error? a. failing to reject the null hypothesis when it is true b. rejecting the null hypothesis when it is true c. rejecting the null hypothesis when it is false d. failing to reject the null hypothesis when it is false
rejecting the null hypothesis when it is true
The frequency relative to the total number of responses is described as: a. cumulative relative frequency b. relative frequency c. cumulative frequency d. frequency
relative frequency
Specific measurements used to compare different values from data sets, or simply comparing data within the same data set, is a. standardization b. relative mean c. relative standing d. sample means
relative standing
Percentile formula is all about a. relativity b. creativity c. statistics d. skewness
relativity
How does the range of the x & y variables affect the correlation? a. expanding the range can lower the correlation b. restricting the range can lower the correlation c. expanding the range can strengthen the correlation d. restricting the range can strengthen the correlation
restricting the range can lower the correlation
A teacher decides to find the first quiz score average of her class of 100 students. To do so, she takes random samples of 5 students and averages their respective scores together. Then she takes random samples of these averaged scores and plots their distribution. What kind of distribution did the teacher create? a. population b. sampling c. sample d. standard normal distribution
sampling
What type of graph would be best to show the correlation between shoe size and height? a. bar graph b. scatter plot c. pie chart d. histogram
scatter plot
To use the standard normal distribution... a. scores must be standardized b. scores must be unstandardized c. the means must not be equated d. variance and standard deviation must equal 0
scores must be standardized
Which of these are NOT an example of descriptive statistics? a. mode b. standard error c. significance d. standard deviation
significance
A t-test can be used to determine which of the following? a. the unstandardized regression b. significance of slope c. error size d. both a and b
significance of slope
What does "b" represent in the regression equation? a. predicted outcome score b. an individual's predictor score c. slope d. y-intercept
slope
In PSYC 210, the mean for the midterm was an 88. What other statistics are important to help interpret this value? a. standard deviation b. Levene's Test c. power d. R(squared) value
standard deviation
What type of measure of variance is measured in raw units? a. range b. standard deviation c. variance
standard deviation
Which of the following is not a measure of central tendency? a. mean b. standard deviation c. mode d. median
standard deviation
When visualizing a sampling distribution compared to a population distribution, how do their standard deviations differ? a. standard deviation of sampling distribution is larger than population distribution b. standard deviation of sampling distribution is smaller than population distribution c. standard deviations are the same d. none of the above
standard deviation of sampling distribution is smaller than population distribution
After gather all the data of differing incomes in North Carolina, which measure of variability would you use to determine the reliability of the mean? a. standard error of the mean b. standard deviation c. variance d. range
standard error of the mean
What is the shape of a standard normal distribution? a. negatively skewed b. positively skewed c. symmetrical d. depends on the data
symmetrical
What test is used to determine the significant of the slope of a linear equation? a. z-test b. t-test c. b-test d. standard deviation test
t-test
Which of these are not part of descriptive statistics? a. central tendencies b. variability c. t-tests d. relative standing
t-tests
You want to see if there is a difference between precipitants' pre-test scores and post-test scores. What should you test for? a. t-test for independent groups b. t-tests for correlated groups c. z-test for independent groups d. z-test for correlated groups
t-tests for correlated groups
As state in the Central Limit Theorem, what happens to the sample mean distribution when the sample size gets larger? a. the distribution is positively skewed b. the distribution is negatively skewed c. the distribution is normal d. the distribution is is platykurtic
the distribution is normal
What is a sample distribution? a. the distribution of multiple samples b. the distribution of scores in a particular sample c. the actual distribution of scores for a population d. the difference between two numbers
the distribution of scores in a particular sample
What might be a problem with using the mean? a. the mean does not give any individuality in analyzing data as a whole (in terms of individual samples) b. since the mean is not affected by outliers, it does not truly represent every single data point c. the mean divides all the samples by the number of samples d. there is no problem with using the mean
the mean does not give any individuality in analyzing data as a whole (in terms of individual samples)
The height of the columns of a bar graph represents... a. mean of scores b. the particular statistical point at category c. the number of scores in a particular category d. the range of scores
the number of scores in a particular category
The kurtosis of a distribution refers to what? a. the peakedness or flatness of a distribution b. the measure of central tendency that best describes a distribution c. whether there are more extreme outliers in one tail of distribution as compared to the other d. how many class intervals a given distribution has
the peakedness or flatness of a distribution
What effect occurs when you increase the population of your sample in standard error? a. standard error increases b. standard error is not affected by the population of a sample c. the standard error decreases d. it cannot be determined without further information
the standard error decreases
What is a property of the mean? a. the sum of the deviation from the mean will always equal zero b. the sum of the deviations from the mean will always be equal to one c. deviations do not take into account the mean d. none of the above
the sum of the deviations from the mean will always equal zero
Researchers want to analyze the relationship between height and shoe size. To do this, they collect data and form a scatterplot. If they discover a positive relationship between the two variables, this means: a. the taller individuals had larger shoe sizes than smaller individuals b. he taller individuals had smaller shoe sizes than smaller individuals c. smaller individuals had similar shoe sizes as the taller individuals d. we can conclude that all people at a given height have larger shoe sizes than those shorter than them
the taller individuals had larger shoe sizes than smaller individuals
What does the hat on the y in the linear equation signify? a. that the y-value is higher than it should be b. the y-value is the exact outcome c. the y-value is a prediction d. the y-value represents the linear relationship between the variables
the y-value is a prediction
If we reject the null hypothesis of the Levene's Test, what does this say about the two samples? a. the variances of the samples are the same of the two populations b. the mean of the samples are the same of the populations c. there are differences between variances of the populations d. there are differences between the means of the two populations
there are differences between variances of the populations
If we were to ask the PSYC 210 class how they feel about spring break, and use it to predict the opinion of college students, would the data collected from the 210 class be a statistic or a parameter? a. this is a parameter because the data is from a sample b. this is a statistic because the data is from a sample c. this is a parameter because the data is from a population d. this is a statistic because the data is from a population
this is a statistic because the data is from a sample
Which of these is NOT an example of a discrete statistic? a. number of seashells on a specific beach b. number of responses from a class survey c. time spent studying in hours, minutes, and seconds d. price of car, in dollars
time spent studying in hours, minutes, and seconds
Which definition best describes percentile rank? a. to describe the number of data points above a particular data point b. to describe what a particular data point means relative to other data points c. to describe the number of data points below a particular data point d. to describe the data point in terms of raw units
to describe what a particular data point means relative to other data points
Why is regression used? a. to determine if the variables are the same b. to find the difference in standard deviation c. compare the means of variables d. to determine if there is a relationship between multiple variables
to determine if there is a relationship between multiple variables
Why do we graph our data? a. to calculate statistics b. to make it harder to understand the data c. to make complex data easier to comprehend d. to determine significance relationships
to make complex data easier to comprehend
When calculating the percentile, what does N represent? a. percentile point b. lower real limit c. total sample size d. partial sample size
total sample size
What is standardization in terms of regression? a. there is no standardizing b. transforming both x and y into z-scores c. deleting the relationship from the variables d. none of the above
transforming both x and y into z-scores
What is being compared in a t-test? a. a sample and a population b. two samples c. two populations d. a population parameter to a population mean
two samples
What conclusions can NOT be drawn from inferential statistics? a. significance b. typical or "average" representation of data c. educated guessed d. all of these are examples of inferential statistics
typical or "average" representation of data
What is an easy and efficient way to simplify large amounts of visual data? a. remove data that doesn't correspond to a number on the x-axis b. use class intervals c. only show data that is relevant to the point you're trying to make d. only display central values
use class intervals
In a study measuring impact of height on athletic ability, height and athletic ability are examples of: a. descriptions b. statistic c. parameter d. variables
variables
Which of the following is an assumption that does NOT have to be assumed for an independent samples t-test? a. samples are drawn for a normal distribution b. variance for each sample are equal c. samples are and random and independent from one another d. variance is only within but not between groups
variance is only within but not between groups
What do percentile ranks describe? a. how standard deviation applies to sample size b. the variability c. the sample size d. what a data point means relative to other points
what a data point means relative to other data points
When would the mode be the most effective way to describe a distribution? a. when data are categorical with few categories b. when the mean, median, and mode are the same and you have a continuous variable c. when the mean, median, and mode are the same and you have a categorical variable d. the mode is never appropriate
when data are categorical with few categories
When do you fail to reject the null hypothesis? a. z-score is greater than 1.96 or less than -1.96 b. when the p-value is greater than 0.05 c. when it falls in the critical region on the graph d. when the standard deviation is greater than 0.05
when the p-value is greater than 0.05
When should you use a t-test as opposed to a z-test? a. when the population standard deviation is known b. when the population standard deviation is unknown c. when the population mean is unknown d. when the sample mean is unknown
when the population standard deviation is unknown
A t-test is recommended in which of the following scenarios? a. when the p-value is less than the significant value b. when you are only given information about the population c. when we do not have information about the population d. when the mean is less than the standard deviation
when we do not have enough information about the population
In what context would you use measures of variability as opposed to measures of central tendency? a. when there are no outliers b. when you're trying to determine the average values c. when you need to understand how the data points differ from each other d. when you have an interval or ratio scale
when you need to understand how the data points differ from each other
A distribution with high variability? a. wider range of values b. smaller range of values c. low standard deviation d. low variance
wider range of values
A frequency distribution graph has frequencies on the ________ axis and the scores on the _______ axis. a. x-axis, y-axis b. y-axis, x-axis
y-axis, x-axis
What part of the regression equation is always constant? a. slope b. differences between observed and predicted scores c. y-intercept d. outcome
y-intercept
What is the critical value for a one-tailed test? a. z = .05 b. z = 5 c. z = 1.96 d. z = 1.65
z = 1.65
Which of these is the correct alternative hypothesis for a two-tailed independent samples t-tests? What does this mean? a. µ1 - µ2 =/= 0; this means that the populations are not independent from one another b. µ1 - µ2 = 0; this means that the populations are independent from one another c. µ1 - µ2 =/= 0; this means that the populations are independent from one another d. M1 - M2 = 0; this means that the populations are not independent from one another
µ1 - µ2 =/= 0; this means that the populations are not independent from one another
