WGU D582 INTRO TO STATS FOR
RESEARCH - HELPFUL TIPS ACTUAL EXAM
PAPER 2026 QUESTIONS WITH ANSWERS
GRADED A+
◍ a rule that provides an approximation for the percentage of data that is
between two values based on the standard deviation; only applies to
bell-shaped distributions.
Answer: empirical rule
◍ A researcher collected data on the type of vehicles (car, truck, SUV,
minivan, other) people drive. The data includes 500 responses among the
five categories. The researcher wants to create a visual display of the data.
What is the appropriate graphical display?.
Answer: bar chart
◍ Data on the relationship between classroom size and cost of supplies was
used to determine an appropriate regression equation of y=253.6+36.5x. In
this equation, x represents classroom size and y represents cost of supplies.
Which interpretation of this regression model is appropriate?.
Answer: an increase of 1 in the classroom size is associated with an increase
in cost of 36.50
◍ A researcher wants to know how many students who take this course use
these lesson quizzes to study. The researcher surveys students who take this
course in February. What is that group of students called.
Answer: non-representative sample because the group in February could
have some inherent similarity causing the group not to be representative of
the population, they should use random sampling if they want a
representative sample
,◍ probability distribution that is approximately bell-shaped.
Answer: normal probability distribution
◍ special percentile that divides ordered data into quarters.
Answer: quartile
◍ a graphical display for frequency distribution based on connected lines.
Answer: frequency polygon
◍ another name for a quantitative variable.
Answer: numerical variable
◍ A researcher conducted a large sample hypothesis test for a difference of
population proportions. The critical values were determined to be -2.576 and
2.576. The test statistic is 3.024. What is the proper conclusion?.
Answer: reject the null hypothesis
◍ Simple Random Sampling.
Answer: A method of sampling in which every member of the population
has an equal probability of being chosen
◍ The scores on a nationally administered standardized test are normally
distributed. Which portion of the data is within two standard deviations of
the mean?.
Answer: 95%
◍ Residual Plot.
Answer: A plot of the difference between actual points in a dataset and the
expected values calculated from the regression line
◍ A middle school teacher wants to determine if 6th grade students are scoring
differently this year on a standardized test compared to previous years. The
mean score of all past students on the standardized test has been 78.2%.
Their current class of 6th graders consists of 23 students and their mean
score on the standardized test was 75.2%. The teacher performed a
two-tailed t-test with a significance level of 0.05. The null hypothesis was
0: There is no difference between the mean score of this year's 6th graders
, and 78.2%, ≠78.2%, and the alternative hypothesis was : There is a
difference between the mean score of this year's 6th graders and 78.2%,
≠78.2%. The study found a t-statistic of —2.398 and a critical value of ±
2.074. What is the appropriate conclusion?.
Answer: Reject the null hypothesis. There is evidence that the mean score of
this year's 6th graders is significantly different from 78.2%.
◍ a numeric data summary that describes a population.
Answer: parameter
◍ A powerful theorem about the sampling distribution of the mean.
Answer: central limit theorem
◍ a range of scores considered plausible based on the standard deviation,
sample size and desired level of confidence.
Answer: confidence interval
◍ What is it called when people are placed in subgroups according to height
and then people within each height group are randomly sampled?.
Answer: stratified random sampling
◍ A display of all the possible outcomes in a dataset along with how often
each occurs.
Answer: frequency distribution
◍ indicates whether the variables change in the same way or in opposite ways'
may be positive or negative.
Answer: direction
◍ a graphical display of a frequency distribution for quantitative data based on
rectangular bars.
Answer: histogram
◍ A college professor gave a final exam to all their students. Each score is out
of 100 possible points. The professor wants to compare the relative
frequencies of test scores for the various grade levels (freshmen,
sophomores, etc.) in a visual way so that the data for each grade level is
, included. What is the appropriate graphical display?.
Answer: frequency polygon
◍ Research is being conducted about early childhood development. Which
variable of the study is discrete?.
Answer: Number of diaper changes in a day
◍ Sampling Distribution.
Answer: Probability distribution for the possible value of a statistic when
random samples are repeatedly selected from the population
◍ What is an example of a continuous variable?.
Answer: the weight of a soil sample in a study about fertilizer
◍ A A researcher is setting up a hypothesis test. Which component is required
for the test?.
Answer: rejection region
◍ A student is conducting research on the study habits of fellow students at a
college. Which variable of the study is quantitative?.
Answer: grade point average
◍ probability of rejecting the null hypothesis is true.
Answer: significance level
◍ A researcher collected data on standardized test scores of 10,000
participants. The researcher wants to be able to see the quartile of the data
and to be able to identify outliers. Which type of graphical display should be
used?.
Answer: box plot
◍ Which description represents the correct interpretation of -0.92 as a
correlation coefficient?.
Answer: strong inverse relationship
◍ Pearson's r.
Answer: A statistic that quantifies how closely two continuous variables are
related in a linear way; the same as the correlation coefficient
RESEARCH - HELPFUL TIPS ACTUAL EXAM
PAPER 2026 QUESTIONS WITH ANSWERS
GRADED A+
◍ a rule that provides an approximation for the percentage of data that is
between two values based on the standard deviation; only applies to
bell-shaped distributions.
Answer: empirical rule
◍ A researcher collected data on the type of vehicles (car, truck, SUV,
minivan, other) people drive. The data includes 500 responses among the
five categories. The researcher wants to create a visual display of the data.
What is the appropriate graphical display?.
Answer: bar chart
◍ Data on the relationship between classroom size and cost of supplies was
used to determine an appropriate regression equation of y=253.6+36.5x. In
this equation, x represents classroom size and y represents cost of supplies.
Which interpretation of this regression model is appropriate?.
Answer: an increase of 1 in the classroom size is associated with an increase
in cost of 36.50
◍ A researcher wants to know how many students who take this course use
these lesson quizzes to study. The researcher surveys students who take this
course in February. What is that group of students called.
Answer: non-representative sample because the group in February could
have some inherent similarity causing the group not to be representative of
the population, they should use random sampling if they want a
representative sample
,◍ probability distribution that is approximately bell-shaped.
Answer: normal probability distribution
◍ special percentile that divides ordered data into quarters.
Answer: quartile
◍ a graphical display for frequency distribution based on connected lines.
Answer: frequency polygon
◍ another name for a quantitative variable.
Answer: numerical variable
◍ A researcher conducted a large sample hypothesis test for a difference of
population proportions. The critical values were determined to be -2.576 and
2.576. The test statistic is 3.024. What is the proper conclusion?.
Answer: reject the null hypothesis
◍ Simple Random Sampling.
Answer: A method of sampling in which every member of the population
has an equal probability of being chosen
◍ The scores on a nationally administered standardized test are normally
distributed. Which portion of the data is within two standard deviations of
the mean?.
Answer: 95%
◍ Residual Plot.
Answer: A plot of the difference between actual points in a dataset and the
expected values calculated from the regression line
◍ A middle school teacher wants to determine if 6th grade students are scoring
differently this year on a standardized test compared to previous years. The
mean score of all past students on the standardized test has been 78.2%.
Their current class of 6th graders consists of 23 students and their mean
score on the standardized test was 75.2%. The teacher performed a
two-tailed t-test with a significance level of 0.05. The null hypothesis was
0: There is no difference between the mean score of this year's 6th graders
, and 78.2%, ≠78.2%, and the alternative hypothesis was : There is a
difference between the mean score of this year's 6th graders and 78.2%,
≠78.2%. The study found a t-statistic of —2.398 and a critical value of ±
2.074. What is the appropriate conclusion?.
Answer: Reject the null hypothesis. There is evidence that the mean score of
this year's 6th graders is significantly different from 78.2%.
◍ a numeric data summary that describes a population.
Answer: parameter
◍ A powerful theorem about the sampling distribution of the mean.
Answer: central limit theorem
◍ a range of scores considered plausible based on the standard deviation,
sample size and desired level of confidence.
Answer: confidence interval
◍ What is it called when people are placed in subgroups according to height
and then people within each height group are randomly sampled?.
Answer: stratified random sampling
◍ A display of all the possible outcomes in a dataset along with how often
each occurs.
Answer: frequency distribution
◍ indicates whether the variables change in the same way or in opposite ways'
may be positive or negative.
Answer: direction
◍ a graphical display of a frequency distribution for quantitative data based on
rectangular bars.
Answer: histogram
◍ A college professor gave a final exam to all their students. Each score is out
of 100 possible points. The professor wants to compare the relative
frequencies of test scores for the various grade levels (freshmen,
sophomores, etc.) in a visual way so that the data for each grade level is
, included. What is the appropriate graphical display?.
Answer: frequency polygon
◍ Research is being conducted about early childhood development. Which
variable of the study is discrete?.
Answer: Number of diaper changes in a day
◍ Sampling Distribution.
Answer: Probability distribution for the possible value of a statistic when
random samples are repeatedly selected from the population
◍ What is an example of a continuous variable?.
Answer: the weight of a soil sample in a study about fertilizer
◍ A A researcher is setting up a hypothesis test. Which component is required
for the test?.
Answer: rejection region
◍ A student is conducting research on the study habits of fellow students at a
college. Which variable of the study is quantitative?.
Answer: grade point average
◍ probability of rejecting the null hypothesis is true.
Answer: significance level
◍ A researcher collected data on standardized test scores of 10,000
participants. The researcher wants to be able to see the quartile of the data
and to be able to identify outliers. Which type of graphical display should be
used?.
Answer: box plot
◍ Which description represents the correct interpretation of -0.92 as a
correlation coefficient?.
Answer: strong inverse relationship
◍ Pearson's r.
Answer: A statistic that quantifies how closely two continuous variables are
related in a linear way; the same as the correlation coefficient
