WGU D582 INTRO TO STATISTICS FOR
RESEARCH OA ACTUAL EXAM PAPER 2026
QUESTIONS WITH ANSWERS GRADED A+
◍ How does the central limit theorem assist in interpreting data?.
Answer: It ensures that sample means follow an approximately normal
distribution regardless of the population distribution.
◍ A team of botanists are conducting a study to understand how light exposure
and watering frequency affect the growth of a particular plant species. They
chose four different light exposures ("Full Sun," "Part Sun," "Part Shade,"
and "Full Shade") and three watering frequencies (daily, every two days,
and weekly). They then measured the growth rate of the 240 plants over 8
weeks split equally among the different treatment groups. The team
performed a two-factor ANOVA. How many degrees of freedom are there
for light exposures, water frequencies, and the interaction term?.
Answer: 3,2, and 9
◍ parameter.
Answer: numerical data that describes the population
◍ linear relation.
Answer: pattern of a scatterplot are in a straight line
◍ range.
Answer: The difference between the largest and smallest values in a dataset
◍ Why should you create and check a residual plot when performing a linear
regression?.
Answer: A residual plot can help you check if the data is well-modeled by a
linear function.
,◍ biased sample.
Answer: sample whose characteristics do not closely match those of the
population
◍ significance level.
Answer: probability of rejecting the null hypothesis when the null
hypothesis is true
◍ What are the five questions to ask when reading science news?.
Answer: 1. What was the sample size? 2. Who was included in the sample?
3. How many studies have been done on this topic? 4. What steps were
taken to mitigate researcher bias? 5. Where else can I find additional
information?
◍ 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.
◍ example of a sample.
Answer: A researcher wants to study the roots of oak trees and chooses 100
trees to dig around to see the roots.
◍ analysis of variance (ANOVA).
Answer: used when comparing three or more population means
◍ standard error of the mean.
Answer: statistic based on the sample standard deviation divided by the
square root of the sample size
◍ What does an ANOVA for linear regression typically assess?.
Answer: The significance of the slope(s) of the regression line
◍ two-factor ANOVA.
Answer: two way analysis of variance that examines the effects of two
, different independent variables on one continuous dependent variable
◍ 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 perform a one-tailed t-test with a significance level of 0.05. The test
produces a t-statistic of 1.8 with a critical value of 1.711. What is the
appropriate conclusion?.
Answer: Reject the null hypothesis. There is evidence that the mean shelf
life of the peas is greater than 4 days: >4
◍ box plot.
Answer: display based on the 25th, 50th, and 75th percentiles of a database
◍ A researcher created a confidence interval but wants to repeat the process
with changes that will decrease the width of the interval. Which change
results in a narrower interval?.
Answer: Decrease the level of confidence
◍ What does statistical power measure in hypothesis testing?.
Answer: The probability of correctly rejecting a null hypothesis when it is
false
◍ standard error of the sample population.
Answer: standard deviation of the sample portion which depends on p,q, and
the sample size
◍ Which of the following would likely reduce sampling error?.
Answer: Increasing the sample size.
◍ variance.
Answer: the average squared difference of the scores from the mean
◍ central limit theorem.
Answer: The theory that, as sample size increases, the distribution of sample
, means of size n, randomly selected, approaches a normal distribution.
◍ statistics.
Answer: numerical data that describes a sample
◍ continuous variables.
Answer: have an infinite amount of values such as temperatures and money
◍ what measurement scales are considered quantitive data.
Answer: interval and ratio
◍ What is reliability in research?.
Answer: The consistency of a measure across time and different contexts.
◍ What is a case study?.
Answer: An in-depth examination of one person or a small number of
people over an extended time period.
◍ outlier.
Answer: an unusual data value that does not fit the rest of the data
◍ 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
◍ what are the three forms in scatterplots.
Answer: linearcurvedno relation
◍ What is the placebo effect?.
Answer: Improvement resulting from mere expectation.
◍ second quartile.
Answer: the 50th percentile of a dataset
RESEARCH OA ACTUAL EXAM PAPER 2026
QUESTIONS WITH ANSWERS GRADED A+
◍ How does the central limit theorem assist in interpreting data?.
Answer: It ensures that sample means follow an approximately normal
distribution regardless of the population distribution.
◍ A team of botanists are conducting a study to understand how light exposure
and watering frequency affect the growth of a particular plant species. They
chose four different light exposures ("Full Sun," "Part Sun," "Part Shade,"
and "Full Shade") and three watering frequencies (daily, every two days,
and weekly). They then measured the growth rate of the 240 plants over 8
weeks split equally among the different treatment groups. The team
performed a two-factor ANOVA. How many degrees of freedom are there
for light exposures, water frequencies, and the interaction term?.
Answer: 3,2, and 9
◍ parameter.
Answer: numerical data that describes the population
◍ linear relation.
Answer: pattern of a scatterplot are in a straight line
◍ range.
Answer: The difference between the largest and smallest values in a dataset
◍ Why should you create and check a residual plot when performing a linear
regression?.
Answer: A residual plot can help you check if the data is well-modeled by a
linear function.
,◍ biased sample.
Answer: sample whose characteristics do not closely match those of the
population
◍ significance level.
Answer: probability of rejecting the null hypothesis when the null
hypothesis is true
◍ What are the five questions to ask when reading science news?.
Answer: 1. What was the sample size? 2. Who was included in the sample?
3. How many studies have been done on this topic? 4. What steps were
taken to mitigate researcher bias? 5. Where else can I find additional
information?
◍ 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.
◍ example of a sample.
Answer: A researcher wants to study the roots of oak trees and chooses 100
trees to dig around to see the roots.
◍ analysis of variance (ANOVA).
Answer: used when comparing three or more population means
◍ standard error of the mean.
Answer: statistic based on the sample standard deviation divided by the
square root of the sample size
◍ What does an ANOVA for linear regression typically assess?.
Answer: The significance of the slope(s) of the regression line
◍ two-factor ANOVA.
Answer: two way analysis of variance that examines the effects of two
, different independent variables on one continuous dependent variable
◍ 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 perform a one-tailed t-test with a significance level of 0.05. The test
produces a t-statistic of 1.8 with a critical value of 1.711. What is the
appropriate conclusion?.
Answer: Reject the null hypothesis. There is evidence that the mean shelf
life of the peas is greater than 4 days: >4
◍ box plot.
Answer: display based on the 25th, 50th, and 75th percentiles of a database
◍ A researcher created a confidence interval but wants to repeat the process
with changes that will decrease the width of the interval. Which change
results in a narrower interval?.
Answer: Decrease the level of confidence
◍ What does statistical power measure in hypothesis testing?.
Answer: The probability of correctly rejecting a null hypothesis when it is
false
◍ standard error of the sample population.
Answer: standard deviation of the sample portion which depends on p,q, and
the sample size
◍ Which of the following would likely reduce sampling error?.
Answer: Increasing the sample size.
◍ variance.
Answer: the average squared difference of the scores from the mean
◍ central limit theorem.
Answer: The theory that, as sample size increases, the distribution of sample
, means of size n, randomly selected, approaches a normal distribution.
◍ statistics.
Answer: numerical data that describes a sample
◍ continuous variables.
Answer: have an infinite amount of values such as temperatures and money
◍ what measurement scales are considered quantitive data.
Answer: interval and ratio
◍ What is reliability in research?.
Answer: The consistency of a measure across time and different contexts.
◍ What is a case study?.
Answer: An in-depth examination of one person or a small number of
people over an extended time period.
◍ outlier.
Answer: an unusual data value that does not fit the rest of the data
◍ 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
◍ what are the three forms in scatterplots.
Answer: linearcurvedno relation
◍ What is the placebo effect?.
Answer: Improvement resulting from mere expectation.
◍ second quartile.
Answer: the 50th percentile of a dataset
