WGU D582 INTRO TO STATS FOR
RESEARCH - HELPFUL TIPS FINAL TEST
2026 QUESTIONS WITH CORRECT
ANSWERS GRADED A+
◍ A bakery wants to ensure the consistency of the weight of their bread
loaves. They sample 50 loaves and calculate 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?.
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.
◍ sampling error.
Answer: The difference between a test statistic and its corresponding
population parameter is caused by differences between the sample and the
overall population
◍ biased sample.
Answer: sample whose characteristics do not closely match those of the
population
◍ hypothesis testing.
Answer: procedure that uses data from a sample to draw a conclusion about
a population
◍ What are potential problems in the Predictive Modeling step?.
Answer: Too many input variables (predictors) can cause
problemsCorrelation does not imply causation.Time series models often
, need sufficient time data to offer precise trending.Predictive model accuracy
should be assessed using cross-validation.
◍ what are the four steps with testing the t statistic and the z statistic.
Answer: state the hypothesisfind the critical valuecompute the test
statisticmake a decision
◍ Timely communication is vital to a project, and what applications are
available for such a thing?.
Answer: SlackTeamsJira
◍ Which tool can easily perform matrix computation as well as optimization?.
Answer: Python
◍ What does a larger standard deviation imply about a dataset?.
Answer: The data points are more spread out from the mean.
◍ what type pf graph does ratio measurement use.
Answer: BarBox plotHistogram (frequency on y axis)Frequency polygon
◍ Suppose you are a quality control manager at a company that packages fresh
snow peas. You want to determine if the packaging methods result in the
snow peas' shelf life being greater than 4 days when stored in a refrigerator.
You choose 25 random packages of snow peas immediately after production
and measure how long the peas last until they are no longer deemed fresh.
You wish to perform a t-test with a significance level of 0.01. What are the
degrees of freedom in this situation?.
Answer: 24
◍ example of interval scale.
Answer: time on a 12 hour clock
◍ ordinal scale.
Answer: a measurement scale that uses categories in a certain order
◍ A marketing team at a company wants to compare a texting campaign to an
email campaign. They send texts to 1000 random customers on their texting
list and 1000 random customers on their email list, only choosing those who
, appear on just one list. Of those who received texts, 120 made a purchase.
Of those who received emails, 100 made a purchase. They perform a
two-tailed hypothesis test comparing the proportion of those who made a
purchase after receiving a text and the proportion of those who made a
purchase after receiving an email with a significance level of 0.05. Their
study produced a -value of 0.15. What is the appropriate conclusion?.
Answer: Fail to reject the null hypothesis. There is no significant difference
between the rates of those who made a purchase after receiving a text versus
an email.
◍ factorial design.
Answer: design that allows researchers to examine the influence of more
than one independent variable on the dependent variable
◍ example of systematic sampling.
Answer: a researcher has a list of all the students in a school district. The
researcher obtains a sample by selecting every 20th student on the list.
◍ curvilinear relation.
Answer: pattern points are curved in a scatterplot (similar to a U shape)
◍ A pharmaceutical company has developed a new drug claimed to be
effective in treating a common medical condition. To assess its efficacy, a
clinical trial is conducted involving a sample of patients diagnosed with the
condition. In a trial of 200 patients, 100 were randomly selected to receive
the new drug, while the remaining 100 received a placebo. An external
researcher determined which patients' conditions improved and which ones
did not. What is the correct null hypothesis for a one-tailed hypothesis test
to determine if the proportion of those who improved after taking the new
drug, 1 was greater than the proportion of those who improved after taking
the placebo, 2?.
Answer: There is no difference in the proportions of those whose conditions
improved and took the new drug and those who took the placebo;
1− 2=0.
◍ example of stratified random sample.
, Answer: What is it called when people are placed in subgroups according to
height and then people within each height group are randomly sampled?
◍ probability value (p-value).
Answer: probability of a certain outcome assuming the null hypothesis is
true
◍ quartile.
Answer: percentile divided into four quarters
◍ what are the three forms in scatterplots.
Answer: linearcurvedno relation
◍ What is a potential problem to consider in the planning phase?
A. Lack of clear focus on stakeholders, timeline, limitations, and budget
B. Quality and type of data may make access more difficult
C. Some cleaning techniques could dramatically change data/outcomes
D. Outliers not dealt with can cause problems with statistical models due to
excessive variability..
Answer: A
◍ example of frequency polygon.
Answer: 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.
◍ This phase often relies on the use of data visualization tools and numerical
summaries, such as the measures of central tendency and variability..
Answer: Data Exploration
◍ What are three things to remember when scraping data?.
Answer: Respect privacyRespect copyrightVisible doesn't mean open
◍ What are two potential problems in the Data Cleaning/Wrangling step?.
Answer: Some cleaning techniques could dramatically change
RESEARCH - HELPFUL TIPS FINAL TEST
2026 QUESTIONS WITH CORRECT
ANSWERS GRADED A+
◍ A bakery wants to ensure the consistency of the weight of their bread
loaves. They sample 50 loaves and calculate 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?.
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.
◍ sampling error.
Answer: The difference between a test statistic and its corresponding
population parameter is caused by differences between the sample and the
overall population
◍ biased sample.
Answer: sample whose characteristics do not closely match those of the
population
◍ hypothesis testing.
Answer: procedure that uses data from a sample to draw a conclusion about
a population
◍ What are potential problems in the Predictive Modeling step?.
Answer: Too many input variables (predictors) can cause
problemsCorrelation does not imply causation.Time series models often
, need sufficient time data to offer precise trending.Predictive model accuracy
should be assessed using cross-validation.
◍ what are the four steps with testing the t statistic and the z statistic.
Answer: state the hypothesisfind the critical valuecompute the test
statisticmake a decision
◍ Timely communication is vital to a project, and what applications are
available for such a thing?.
Answer: SlackTeamsJira
◍ Which tool can easily perform matrix computation as well as optimization?.
Answer: Python
◍ What does a larger standard deviation imply about a dataset?.
Answer: The data points are more spread out from the mean.
◍ what type pf graph does ratio measurement use.
Answer: BarBox plotHistogram (frequency on y axis)Frequency polygon
◍ Suppose you are a quality control manager at a company that packages fresh
snow peas. You want to determine if the packaging methods result in the
snow peas' shelf life being greater than 4 days when stored in a refrigerator.
You choose 25 random packages of snow peas immediately after production
and measure how long the peas last until they are no longer deemed fresh.
You wish to perform a t-test with a significance level of 0.01. What are the
degrees of freedom in this situation?.
Answer: 24
◍ example of interval scale.
Answer: time on a 12 hour clock
◍ ordinal scale.
Answer: a measurement scale that uses categories in a certain order
◍ A marketing team at a company wants to compare a texting campaign to an
email campaign. They send texts to 1000 random customers on their texting
list and 1000 random customers on their email list, only choosing those who
, appear on just one list. Of those who received texts, 120 made a purchase.
Of those who received emails, 100 made a purchase. They perform a
two-tailed hypothesis test comparing the proportion of those who made a
purchase after receiving a text and the proportion of those who made a
purchase after receiving an email with a significance level of 0.05. Their
study produced a -value of 0.15. What is the appropriate conclusion?.
Answer: Fail to reject the null hypothesis. There is no significant difference
between the rates of those who made a purchase after receiving a text versus
an email.
◍ factorial design.
Answer: design that allows researchers to examine the influence of more
than one independent variable on the dependent variable
◍ example of systematic sampling.
Answer: a researcher has a list of all the students in a school district. The
researcher obtains a sample by selecting every 20th student on the list.
◍ curvilinear relation.
Answer: pattern points are curved in a scatterplot (similar to a U shape)
◍ A pharmaceutical company has developed a new drug claimed to be
effective in treating a common medical condition. To assess its efficacy, a
clinical trial is conducted involving a sample of patients diagnosed with the
condition. In a trial of 200 patients, 100 were randomly selected to receive
the new drug, while the remaining 100 received a placebo. An external
researcher determined which patients' conditions improved and which ones
did not. What is the correct null hypothesis for a one-tailed hypothesis test
to determine if the proportion of those who improved after taking the new
drug, 1 was greater than the proportion of those who improved after taking
the placebo, 2?.
Answer: There is no difference in the proportions of those whose conditions
improved and took the new drug and those who took the placebo;
1− 2=0.
◍ example of stratified random sample.
, Answer: What is it called when people are placed in subgroups according to
height and then people within each height group are randomly sampled?
◍ probability value (p-value).
Answer: probability of a certain outcome assuming the null hypothesis is
true
◍ quartile.
Answer: percentile divided into four quarters
◍ what are the three forms in scatterplots.
Answer: linearcurvedno relation
◍ What is a potential problem to consider in the planning phase?
A. Lack of clear focus on stakeholders, timeline, limitations, and budget
B. Quality and type of data may make access more difficult
C. Some cleaning techniques could dramatically change data/outcomes
D. Outliers not dealt with can cause problems with statistical models due to
excessive variability..
Answer: A
◍ example of frequency polygon.
Answer: 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.
◍ This phase often relies on the use of data visualization tools and numerical
summaries, such as the measures of central tendency and variability..
Answer: Data Exploration
◍ What are three things to remember when scraping data?.
Answer: Respect privacyRespect copyrightVisible doesn't mean open
◍ What are two potential problems in the Data Cleaning/Wrangling step?.
Answer: Some cleaning techniques could dramatically change
