WGU D582 Intro to Statistics for Research NEWEST
2026-2027 ACTUAL EXAM COMPLETE 280
QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS) ALREADY
GRADED A+ BRAND NEW!!
A A researcher is setting up a hypothesis test. Which component is required for the test? -
CORRECT ANSWER: rejection region
A bakery wants to ensure the consistency of the weight of their bread loaves. They sample 50
loaves and calculates the mean weight, finding it to be 500 grams with a standard deviation of 20
grams, Which statement best describes the application of the central limit theorem in this
scenario? - CORRECT ANSWER: since the sample size of 50 is greater than 30, the central limit
theorem implies that the DSM will be approximately normally distributed, regardless of the
shape of the population distribution of all bread loaf weights
A casino manager is interested in understanding the behavior of slot machines in their
establishment. They observe that over 10,000 spins of a particular slot machines, the average
payout per spin converges to the theoretical payout per spin value programmed into the machine.
What principle does this observation best illustrate? - CORRECT ANSWER: the law of large
numbers
A chi-square test for homogeneity was performed on data to test the null hypothesis that each
category has an equal probability of being chosen at the 0.04 significance level. The chi-square
results were x2= 4.74, df= 6, and p-value= 0.5782. Which conclusion should be made? -
CORRECT ANSWER: Fail to reject the null hypotheses, the education level and program type
are independent.
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? - CORRECT ANSWER: frequency polygon
,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 race
levels (freshmen, sophomores, etc.) in a visual way so that the data for each grade level is
included. Which type of graphical display should be used - CORRECT ANSWER: frequency
polygon because its used to show the shape of distributions when comparing sets of data
A completely randomized design is used to compare memory test performances of test
participants under three conditions: 8 hours of sleep, 6 hours of sleep, and 4 hours of sleep. Eight
adults are randomly selected for each of the three conditions, and the three resulting mean scores
are compared. The results of a one-way ANOVA provide an F-statistic of 0.265 and a critical F-
value of 0.371. What is the appropriate conclusion? - CORRECT ANSWER: none of the mean
scores are significantly different
A completely randomized design is used to compare numerical list memorization performance
under three conditions: a single exposure to the list, one exposure per day, and five exposures per
day. Twenty students are randomly selected for each of the three conditions, and the three
resulting mean scores are compared. The results of a one-way ANOVA provide an F-statistic of
0.648 and a critical F-value of 0.251. Which conclusion is appropriate for these results? -
CORRECT ANSWER: At least one pairing of mean scores has a significant difference
A display of all the possible outcomes in a dataset along with how often each occurs -
CORRECT ANSWER: frequency distribution
A function with area under the curve describes the probability of outcomes of a random variable
- CORRECT ANSWER: probability distribution
a graphical display for frequency distribution based on connected lines - CORRECT ANSWER:
frequency polygon
a graphical display of a frequency distribution for quantitative data based on rectangular bars -
CORRECT ANSWER: histogram
,a hypothesis that there is an effect of a treatment, a relation between variables, or a difference
between the sample value and the population value - CORRECT ANSWER: alternative
hypothesis
A hypothesis that there is no effect of a treatment, no relation between variables, or no difference
between the sample value and the population value - CORRECT ANSWER: null hypothesis
A large-sample hypothesis test for a difference of population proportions was designed by a
researcher. The critical values are -1.282 and 1.282, and the test statistic is 0.497. Which
conclusion should the researcher make? - CORRECT ANSWER: fail to reject the null hypothesis
a manageable subset of the population - CORRECT ANSWER: sample
A measure of relative position in a dataset; the number of standard deviations a value lies from
the mean of a dataset - CORRECT ANSWER: z-score
a measure of relative position within a dataset; for example, the kth percentile gives a value such
that k% of all values in the dataset fall below that particular value - CORRECT ANSWER:
percentile
a measurement of spread that is based on how each of the values in a dataset deviate from the
mean and can be thought of as the average of the deviations - CORRECT ANSWER: standard
deviation
a measurement scale that uses categories in a certain order - CORRECT ANSWER: ordinal scale
A measurement scale that uses names or categories without ordering them - CORRECT
ANSWER: nominal scale
A method of hypothesis testing that used the mean of a normally distributed, small sample if the
standard deviation of the population is unknown - CORRECT ANSWER: student's t-test
, a method of sampling in which every member of the population has an equal probability of being
chosen - CORRECT ANSWER: simple random sampling
a method of sampling in which members of the population are placed in subgroups or strata, after
which each subgroup is randomly sampled in a way that is proportional to the subgroup's size
relative to the population - CORRECT ANSWER: stratified random sampling
a method of sampling in which the sample is collected based on subjects being willing and
available - CORRECT ANSWER: convenience sampling
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 𝐻0: There is no difference between the
mean score of this year's 6th graders and 78.2%, 𝜇≠78.2%, and the alternative hypothesis was
𝐻𝑎: There is a difference between the mean score of this year's 6th graders and 78.2%, 𝜇≠78.2%.
The study found a t-statistic of —2.398 and a critical value of ± 2.074. What is the appropriate
conclusion? - CORRECT 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 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 76.2%. The teacher calculates a 95%, two-tailed
confidence interval using the t-distribution which produces the values (72.605 and 77.794). How
should the confidence interval be interpreted? - CORRECT ANSWER: If we were to collect
more samples under the same conditions, 95% of the confidence intervals would capture the true
population mean score.
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 76.2%. The teacher calculates a 95%, two-tailed
2026-2027 ACTUAL EXAM COMPLETE 280
QUESTIONS AND CORRECT DETAILED
ANSWERS (VERIFIED ANSWERS) ALREADY
GRADED A+ BRAND NEW!!
A A researcher is setting up a hypothesis test. Which component is required for the test? -
CORRECT ANSWER: rejection region
A bakery wants to ensure the consistency of the weight of their bread loaves. They sample 50
loaves and calculates the mean weight, finding it to be 500 grams with a standard deviation of 20
grams, Which statement best describes the application of the central limit theorem in this
scenario? - CORRECT ANSWER: since the sample size of 50 is greater than 30, the central limit
theorem implies that the DSM will be approximately normally distributed, regardless of the
shape of the population distribution of all bread loaf weights
A casino manager is interested in understanding the behavior of slot machines in their
establishment. They observe that over 10,000 spins of a particular slot machines, the average
payout per spin converges to the theoretical payout per spin value programmed into the machine.
What principle does this observation best illustrate? - CORRECT ANSWER: the law of large
numbers
A chi-square test for homogeneity was performed on data to test the null hypothesis that each
category has an equal probability of being chosen at the 0.04 significance level. The chi-square
results were x2= 4.74, df= 6, and p-value= 0.5782. Which conclusion should be made? -
CORRECT ANSWER: Fail to reject the null hypotheses, the education level and program type
are independent.
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? - CORRECT ANSWER: frequency polygon
,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 race
levels (freshmen, sophomores, etc.) in a visual way so that the data for each grade level is
included. Which type of graphical display should be used - CORRECT ANSWER: frequency
polygon because its used to show the shape of distributions when comparing sets of data
A completely randomized design is used to compare memory test performances of test
participants under three conditions: 8 hours of sleep, 6 hours of sleep, and 4 hours of sleep. Eight
adults are randomly selected for each of the three conditions, and the three resulting mean scores
are compared. The results of a one-way ANOVA provide an F-statistic of 0.265 and a critical F-
value of 0.371. What is the appropriate conclusion? - CORRECT ANSWER: none of the mean
scores are significantly different
A completely randomized design is used to compare numerical list memorization performance
under three conditions: a single exposure to the list, one exposure per day, and five exposures per
day. Twenty students are randomly selected for each of the three conditions, and the three
resulting mean scores are compared. The results of a one-way ANOVA provide an F-statistic of
0.648 and a critical F-value of 0.251. Which conclusion is appropriate for these results? -
CORRECT ANSWER: At least one pairing of mean scores has a significant difference
A display of all the possible outcomes in a dataset along with how often each occurs -
CORRECT ANSWER: frequency distribution
A function with area under the curve describes the probability of outcomes of a random variable
- CORRECT ANSWER: probability distribution
a graphical display for frequency distribution based on connected lines - CORRECT ANSWER:
frequency polygon
a graphical display of a frequency distribution for quantitative data based on rectangular bars -
CORRECT ANSWER: histogram
,a hypothesis that there is an effect of a treatment, a relation between variables, or a difference
between the sample value and the population value - CORRECT ANSWER: alternative
hypothesis
A hypothesis that there is no effect of a treatment, no relation between variables, or no difference
between the sample value and the population value - CORRECT ANSWER: null hypothesis
A large-sample hypothesis test for a difference of population proportions was designed by a
researcher. The critical values are -1.282 and 1.282, and the test statistic is 0.497. Which
conclusion should the researcher make? - CORRECT ANSWER: fail to reject the null hypothesis
a manageable subset of the population - CORRECT ANSWER: sample
A measure of relative position in a dataset; the number of standard deviations a value lies from
the mean of a dataset - CORRECT ANSWER: z-score
a measure of relative position within a dataset; for example, the kth percentile gives a value such
that k% of all values in the dataset fall below that particular value - CORRECT ANSWER:
percentile
a measurement of spread that is based on how each of the values in a dataset deviate from the
mean and can be thought of as the average of the deviations - CORRECT ANSWER: standard
deviation
a measurement scale that uses categories in a certain order - CORRECT ANSWER: ordinal scale
A measurement scale that uses names or categories without ordering them - CORRECT
ANSWER: nominal scale
A method of hypothesis testing that used the mean of a normally distributed, small sample if the
standard deviation of the population is unknown - CORRECT ANSWER: student's t-test
, a method of sampling in which every member of the population has an equal probability of being
chosen - CORRECT ANSWER: simple random sampling
a method of sampling in which members of the population are placed in subgroups or strata, after
which each subgroup is randomly sampled in a way that is proportional to the subgroup's size
relative to the population - CORRECT ANSWER: stratified random sampling
a method of sampling in which the sample is collected based on subjects being willing and
available - CORRECT ANSWER: convenience sampling
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 𝐻0: There is no difference between the
mean score of this year's 6th graders and 78.2%, 𝜇≠78.2%, and the alternative hypothesis was
𝐻𝑎: There is a difference between the mean score of this year's 6th graders and 78.2%, 𝜇≠78.2%.
The study found a t-statistic of —2.398 and a critical value of ± 2.074. What is the appropriate
conclusion? - CORRECT 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 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 76.2%. The teacher calculates a 95%, two-tailed
confidence interval using the t-distribution which produces the values (72.605 and 77.794). How
should the confidence interval be interpreted? - CORRECT ANSWER: If we were to collect
more samples under the same conditions, 95% of the confidence intervals would capture the true
population mean score.
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 76.2%. The teacher calculates a 95%, two-tailed
