Ashford PSY325 2021 June All Weekly Reviews Latest

PSY325 Statistics for the Behavioral & Social Sciences

Week 1 Weekly Review   

Question 1 “Any subset of a population,” defines which?

  An inferential statistic

  A sample

  A parameter

  A distribution

Question 2A normal distribution is mesokurtic.

  True

  False

Question 3Which measure of central tendency gives the “middle score” or “mid-point?”

  mean

  median

  mode

  all of the above

Question 4In a graph, the “point of origin” marks which?

  The point where any graphed line begins

  The point at which x = 0 and y = 0

  The point marking the maximum value in a graph

  The point marking the minimum value in a graph

Question 5How many scores are being summarized in this row of stem-and-leaf display: 6|1349?

  4

  5.

  1,349

  61,349

Question 6 “Data scale” refers to which of the following?

  The level of analysis involved in a statistics problem

  The degree to which the analyst relies on parameters

  The kind of information that data values provide

  The degree to which data values can be calculated

Question 7In statistical notation, Greek letters refer to which of the following?

  Concepts that are important to the procedure

  Statistics that must be calculated

  Procedures or values used repeatedly

  Procedures for which the value is unknown

Question 8The bell curve is actually which of the following?

  An ungrouped frequency distribution

  A special bar graph

  A frequency polygon

  An abscissa

Question 9The bell-shaped curve is also a frequency polygon.

  True

  False

Question 10 We have the following values in a stem-and-leaf display: 2, 10, 14, 16, 17, 22, 23, 29. How many stems will there be?

  15

  8

  3

  1

 

PSY325 Statistics for the Behavioral & Social Sciences

Week 2 Weekly Review   

Question 1How many categories can a variable in a chi-square test have?

  1

  2

  3

  unlimited

Found in Chapter 10 in section 10.2, The Chi-Square Tests

 

 Question 2The table used to organize the data in a chi-square test of independence is called a _____.

  significance table

  contingency table

  continuity table

  effect table

 Question 3The chi-square test of independence has how many variables?

  1

  2

  3

  unlimited

 Question 4Chi-square tests are designed to use which scale of data?

  Nominal

  Ordinal

  Interval

  Ratio

 Question 5The phi coefficient is appropriate to use to determine the strength of the relationship between two nominal variables when the chi-square test of independence is statistically significant AND _____.

  at least one of the variables has only two levels.

  there are at least 5 degrees of freedom.

  both variables have three or more levels.

  the chi-square value is negative.

 Question 6Cramer’s V should be used to determine the strength of the relationship between two nominal variables when the chi-square test of independence is statistically significant AND _____.

  at least one of the variables has only two levels.

  there are at least 5 degrees of freedom.

  both variables have three or more levels.

  the chi-square value is negative.

 Question 7Which of these variables is likely to be on a nominal scale?

  grade-point average

  height

  weight

  college major

 Question 8A chi-square test compares expected frequencies to _____.

  observed frequencies

  theoretical frequencies

  the normal distribution

  nonequivalent frequencies

 Question 9In the 1 x k and r x k chi-square tests, the k represents _____.

  the number of columns or categories in the problem.

  the kurtosis of the distribution.

  the correlation coefficient.

  the contingency coefficient.

 Question 10Two kinds of chi-square tests are which?

  Goodness-of-fit and independent t-test

  Goodness-of-fit and test of independence

  Test of independence and regression

  Correlation and regression

 

PSY325 Statistics for the Behavioral & Social Sciences

Week 3 Weekly Review   

Question 1The measure of variability within the group in a z-test is the population mean, μ.

  True

  False

 Question 2A statistically significant outcome in a z-test indicates which of the following?

  The sample is not characteristic of the population

  The sample could not have been randomly selected

  The sample is characteristic of the population

  The sample represents other samples in the original population

 Question 3“Random selection” refers to which of the following?

  Selecting in order to accommodate each of the major subgroups

  Selecting every “nth” person so as to be representative

  Selecting the most convenient group

  Selecting so that everyone has an equal chance of inclusion

 Question 4In a distribution for which the mean is 25 and the standard deviation is 5, what percentage of all scores occur between 20 and 30?

  34.13%

  68.26%

  84.13%

  92.39%

 Question 5A z score of 2.0 is two standard deviations above the mean of the distribution (t).

  True

  False

 Question 6A distribution where the mean and std. deviation have pre-determined values calls for which?

  Raw scores

  z scores

  Modified standard scores

  Percentile rankings

 Question 7The central limit theorem maintains which?

  All data in a population are normal

  Any distribution can be turned into a z distribution

  All values tend toward the center of the distribution

  Distributions based on samples tend to be normal

 Question 8If you took a test, your standard score would indicate how many standard deviations you ended up away from the ______.

  Mean

  High Score

  Low score

  Median

 Question 9What are the common elements among z scores, the z-test, and the t-tests?

  All require ordinal scale data

  All have measures of within-group variability in the numerator

  They’re all tests of significant differences

  All the numerators are difference scores

 Question 10In the t-test, the dependent variable is nominal scale.

  True

  False

 

PSY325 Statistics for the Behavioral & Social Sciences

Week 4 Weekly Review   

Question 1Repeated measures designs reduce error variance as long as the scores are correlated.

  True

  False

 Question 2If there were 4 groups, how many possible pair-wise comparisons are there?

  3

  4

  5

  6

 Question 3In a two-group test, if a t is significant, the F will always be as well.

  True

  False

 Question 4Repeated measures designs increase the degrees of freedom involved in an analysis.

  True

  False

 Question 5What is a “confounding variable?”

  A variable which causes variance but is uncontrolled

  A variable which is mathematically controlled in an analysis

  A variable which is controlled but not measured

  A variable which correlates with other analyses

 Question 6Post-hoc tests identify the location of significant differences in an ANOVA.

  True

  False

 

Question 7The sum of squares, the standard deviation, the variance, and the range are all measures of data variability.

  True

  False

 Question 8The magnitude of any sum of square value reflects which of the following?

  The treatment effect

  The impact of the dependent variable

  The number of scores included

  The effect size

Question 9What measure of data variability did Fisher rely on for ANOVA?

  The F ratio

  The modified standard score

  The squared difference between particular values and the relevant mean

  The standard error of the difference between multiple groups

 Question 10Besides the tedium involved in performing all possible comparisons, what is the problem in conducting all possible t-test with multiple groups?

  Mounting alpha error

  Mounting beta error

  Locating significance

  Determining the effect size

 

PSY325 Statistics for the Behavioral & Social Sciences

Week 5 Weekly Review   

Question 1A one-sample t value is statistically significant in which situation?

  The calculated t is equal to, or larger than the table value

  The calculated t is equal to or smaller than the table value

  The calculated t is equal to or smaller than .05

  The calculated t is equal to or larger than .05

 Question 2What is the similarity between the z test and the one-sample t-test?

  They both analyze differences between sample means

  They both analyze differences between a sample and a population

  They both determine the strength of the relationship between variables

  They both rely on ordinal scale data

 Question 3Turning raw scores into z scores accomplishes all of the following except which?

  Allows for scores from different tests to be compared directly

  Creates a common distribution where the mean is 0

  Creates a common distribution where the standard deviation is 1.0

  Makes the data involved in the transformation normal

Question 4The independent variable in either a before/after t

or a within subjects F is always of what data scale?

  Nominal

  Ordinal

  Interval

  Ratio

 Question 5Which lower-case letter is usually used to represent a correlation coefficient?

  n

  r

  p

  z

 Question 6How is the z-test different from z-score analysis?

  The z-test compares a sample to a population

  The z-test calculates a value of z which can be compared to Table A

  The z-test provides a way to evaluate how individuals compare to a population

  The z-test is based on how individual scores compare to a sample mean

 Question 7More widely scattered points in the scatter-plot indicate which?

  More variability in the x

variable

  More variability in the y

variable

  Normality in both variables

  Weaker relationships between variables

 Question 8Each point in a scatter plot represents which of the following?

  A predicted value

  A measure of either the x or the y variable

  The group to which the measure belongs

  The measure of both variables

 Question 9The chi-square test of independence has how many variables?

  1

  2

  3

  unlimited

 Question 10A type II decision error occurs in which of the following circumstances?

  the decision not to proceed with an analysis

  the decision to proceed when the analysis is flawed

  erroneously determining that a result is not significant

  erroneously determining that a result is significant

 Question 11Rejecting the null hypothesis is the same as saying which?

  Any differences are random differences

  The result is statistically significant

  The hypothesis of difference is rejected

  The research hypothesis is rejected

 Question 12In the set of numbers 2, 3, 3, 4, 4, 4, 5, 5, 6, which is the median?

  3

  4

  5

  6

 Question 13Another name for nominal data is _____.

  continuous

  categorical

  open-ended

  parametric

 Question 14Which of the following defines the intercept value in a regression solution?

  The value of y when x = 0

  The degree of error in the prediction

  The negative impact of x on y

  The change in y from +1.0 in x

 Question 15Which of the following is not a measure of central tendency?

  Mean

  Range

  Median

  Mode

 Question 16How are degrees of freedom related to critical values of rxy?

  Critical values increase in direct proportion to degrees of freedom

  Critical values decline as degrees of freedom increase

  Critical values are such that significance is difficult to establish with large samples

  Critical values allow degrees of freedom to be ignored in large samples

 Question 17What is the normality requirement for ordinary least squares regression?

  Both variables must be drawn from samples which are ordinal

  The solution must fit a normal distribution

  The populations from which the samples come must be normal

  Ordinary least square regression has no normality requirement

 Question 18The answer to which question defines the coefficient of determination, r2?

  What is the statistical relationship between x and y?

  How linear is the relationship between xand y?

  How much of y can be explained by changes in x?

  What is the variation in the x/yrelationship due to chance?

 Question 19The range of possible correlation values for the Pearson Correlation is which?

  From 0 to 1.0

  From 0 to 10.0

  From -.5 to +.5

  From -1.0 to +1.0

 Question 20Grouping people by their political party membership constitutes data of what scale?

  Nominal

  Ordinal

  Interval

  Ratio