Download Statistical Significance and Hypothesis Testing and more Exams Nursing in PDF only on Docsity!
202 5 NSG 522 Mid-Term Exam New Latest Version
with All Questions from Actual Exam and 100%
Correct Answer
The mean is the number in the middle of the observations, when the observations are arranged from smallest to largest. ----------- Correct Answer ---------- False The best way to determine whether data are normally distributed is to A. Construct a box and whisker plot with turkey fences B. Construct a histogram C. Perform a shapiro-wilk test D. Perform a test for outliers ----------- Correct Answer ---------- C. Perform a shapiro wilk test A study can only have one dependent variable ----------- Correct Answer ---------- False Which of the following can be determined from a Spearman correlation coefficient and its associated with p-value? SELECT ALL THAT APPLY Statistical significance Risk of a type 2 error Strength of the relationship Direction of the relationship ----------- Correct Answer ---------- Statistical significance Strength of the relationship Direction of the relationship Which of the following are parametric tests? SELECT ALL THAT APPLY
- repeated-measures ANOVA
- Paired t-test
- McNemar test
- Pearson Correlation coefficient
- Wilcoxon signed-rank ------------ Correct Answer ----------- repeated-measures ANOVA Paired t-test Pearson When comparing hemoglobin A-1C measurements that are normally distributed with no outliers in 2 independent groups, use which of the following tests? A. Fisher exact B. Pearson correlation C. Independent t-test D. Kruskal-Wallis ANOVA ------------ Correct Answer ----------- Independent t-test T/F The interpretation of a p-value varies depends on what statistical test was used to obtain the
p-value. ------------ Correct Answer ----------- False Which of the following can be determined from a Spearman correlation coefficient and its associated p-value? SELECT ALL THAT APPLY
- statistical significance
- risk of a type 2 error
- strength of the relationship
- direction of the relationship ------------ Correct Answer ----------- - statistical significance
- strength of the relationship
- direction of the relationship Which of the following are non-parametric tests? SELECT ALL THAT APPLY
- Chi-square
- Dependent t-test
- Spearman
- One-way analysis of variance
- Mann-Whitney ------------ Correct Answer ----------- - Chi-square
- Spearman
- Mann-Whitney A researcher studies the relationship between hours of television watching and BMI. The correlation coefficient is 0.35. This relationship is: A. moderate inverse B. weak positive C. strong positive D. moderate positive ------------ Correct Answer ----------- D. moderate positive Which of the following would be reasons to use a non-parametric test? SELECT ALL THAT APPLY
- interval data
- Shapiro-Wilk value of 0.
- presence of one small outlier
- normal distribution
- nominal data ------------ Correct Answer ----------- - Shapiro-Wilk value of 0.
- presence of one small outlier
- nominal data Which of the following are nonparametric tests? SELECT ALL THAT APPLY Chi Square test Dependent t test Spearman correlation coefficient
99% ----------- Correct Answer ---------- 95% The validity of a weight measurement obtained with an electronic scale refers to the repeatability of the measurement ----------- Correct Answer ---------- False The quality of life is measure on a scale of 1 (extremely poor quality) to 5 (best possible quality). The best graphic display of these measurements would be a Bar chart Stem and leaf plot Box and whisker plot Histogram ----------- Correct Answer ---------- Histogram What percentage of scores fall between the first and third quartile? 25% 50% 68% 75% 100% ----------- Correct Answer ---------- 50% When analyzing the variable gender, which was measured in 5 categories- the data should be displayed using a histogram box and whisker plot pie chart bar chart line chart ----------- Correct Answer ---------- bar chart a variable was coded as disease present, disease not present, or disease status unknown. When performing the descriptive statistics, which of the following should be used? SELECT ALL THAT APPLY Median Percentages Proportions Frequencies Mode ----------- Correct Answer ---------- Percentages Frequencies A student conducting a quality improvement project on a unit in the university hospital where the
student is enrolled. Since the project is required by the university, the student does not need to obtain additional permission for the project ----------- Correct Answer ---------- False Height recorded in centimeters should be displayed using. SELECT ALL THAT APPLY Bar chart Box and whisker plot Stem and leaf plot Histogram ----------- Correct Answer ---------- Box and whisker plot Stem and Leaf plot Histogram If a hypothesis test identifies a statistically significant finding, that means that the finding is clinically significant and should be implemented into clinical practice as soon as possible --------- -- Correct Answer ---------- False A sample is... A. Selected from the population of interest using a random process B. Best selected by using a nonprobability sampling methods C. A subset of the population of interest D. Best selected by using a purposive sampling ----------- Correct Answer ---------- C. A subset of the population of interest Which of the following p-values is/are statistically significant when alpha is set at 0.05? SELECT ALL THAT APPLY 0.0Q
0.500 ----------- Correct Answer ---------- 0. A small sample size A. Increases the risk of both type 1 and type 2 errors B. Has no effect on the results of a statistical test C. Increases the risk of a type 2 error D. Increases the risk of a type 1 error ----------- Correct Answer ---------- C. Increases the risk of a type 2 error the 95% confidence interval for the mean of a set of observations indicates that 95% of the observations fall within the confidence interval ----------- Correct Answer ---------- False A researcher determines that the results of a hypothesis test are statistically significant. This means that the p-value from the test is
A. A nonprobability sample B. A quota sample C. A simple random sample D. A convenience sample ----------- Correct Answer ---------- C. A simple random sample When performing a hypothesis test to compare groups, a type 1 error is made when a researcher A. Rejects the alternative hypothesis B. Concludes that there is a significant difference between groups when there really is not a difference C. Accepts the null hypothesis D. Concludes that there is not a statistically significant difference when there really is a difference ----------- Correct Answer ---------- B. Concludes that there is a significant difference between groups when there really is not a difference When performing a hypothesis test, a type 2 error occurs when the researcher incorrectly A. Accepts the alternative hypothesis B. Concludes that the findings are not statistically significant C. Rejects the null hypothesis D. Concludes that the findings are statistically significant ----------- Correct Answer ---------- B. Concludes that the findings are not statistically significant A 95% confidence interval for a mean indicates A. 95% of the observations are located within the interval B. there is a 95% chance that the finding is statistically significant C. We can be 95% confident that the true population mean lies within the interval D. All of the above ----------- Correct Answer ---------- c. We can be 95% confident that the true population mean lies within the interval Nonprobability samples are selected using a random process ----------- Correct Answer ---------- False Which of the following sampling methods would provide the best representation of a population with the following racial compisition: 68% white, 15% African American, 12% Hispanic, 5% Asian Cluster sample Simple random sample Quota sample Stratified random sample ----------- Correct Answer ---------- stratified random sample A 95% confidence interval for the mean of a set of height measurement is 62.9 and 64.5 inches. This finding means that
A.There is a 5% chance of a type 1 error B. We can be 95% confident that the true populations mean is between 62.9 and 64.5 inches C. The confidence interval is not statistically significant D. 95% of the observations in the data set are between 62.9 and 64.5 inches. ----------- Correct Answer ---------- B. We can be 95% confident that the true populations mean is between 62.9 and 64.5 inches The standard error of the mean is a measure of the spread of observations around the mean of the observations ----------- Correct Answer ---------- False Which of the following are probability samples? SELECT ALL THAT APPLY Cluster Sample Stratified random sample Quota sample Convenience sample Systematic sample ----------- Correct Answer ---------- Systematic sample cluster sample stratified random sample When alpha is set at .05, that means that A. There is a 95% chance of making a type 2 error B. Only p-values >.05 are statistically significant C. There is a 5% chance of making a type 1 error D. There is a 5% chance of incorrectly accepting the null hypothesis ----------- Correct Answer -- -------- C. There is a 5% chance of making a type 1 error The null hypothesis always stats that there is no relationship between the variables or differences between the groups ----------- Correct Answer ---------- True A clinical nurse specialist is comparing two post op pain management strategies to determine whether there is a difference between the 2 strategies in cost of care, length of hospital stay, and patient satisfaction with care. Which of the following is/are dependent variables in this study? Satisfaction with care Cost of care Pain management strategy Clinical Nurse Specialist Length of hospital stay ----------- Correct Answer ---------- Satisfaction with care Cost of care Length of hospital stay An analysis of variance results in p-value of 0.50. The researcher should conclude that A.There is a statistically significant difference between the groups.
d. Stem-and-leaf plot. e. Bar chart. f. Any/all of the above ----------- Correct Answer ---------- A. Box and whisker plot with Turkey fences The most frequently occurring number in a set of numbers is the a. Median b. Mode. c. Midrange d. Frequency e. 50th percentile ----------- Correct Answer ---------- b. mode The decision to use the mean or median is based upon (Select all that apply) A. Whether the data are normally distributed b. Which statistical tests will be used for hypothesis testing c. The presence or absence of outliers d. The guidelines of the journal where the data will be published ----------- Correct Answer ------- --- A. Whether the data are normally distributed B. The presence or absence of outliers When a continuous variable has a normal distribution and only 1 small outlier, the mean and standard deviation should be used to describe the variable ----------- Correct Answer ---------- False Match the following variables to the correct level of measurement (A. Interval, B. Nominal, C. Ratio, D. Ordinal) Temperature in Fahrenheit Presence or Absence of disease Weight in ounces Race Quality of life (1-5) Hemoglobin A1C Time in Minutes Level of education Oxygen Saturation Blood type ----------- Correct Answer ---------- Temperature in Fahrenheit- A. Interval Presence or Absence of disease- B. Nominal Weight in ounces- C. Ration Race- B. Nominal Quality of life (1-5)- D. Ordinal Hemoglobin A1C- C. Ratio Time in Minutes- C. Ratio Level of education- D. Ordinal Oxygen Saturation- C. Ratio Blood type- B. Nominal
A conceptual definition defines how a variable will be measured, and includes the equipment and procedures that are used in the measurement ----------- Correct Answer ---------- False Testing a new piece of equipment to ensure that the equipment consistently provides that same measurement when the same variable is measured multiple times is an example of Accuracy Validity Reliability All of the above ----------- Correct Answer ---------- Reliability Bar charts and histograms can both be used to describe interval level data ----------- Correct Answer ---------- False All studies need appropriate permission to examine data ----------- Correct Answer ---------- True When comparing hemoglobin A1C measurements that re normally distributed with no outliers in 2 independent groups, the researcher should use which of the following? Fisher exact pearson correlation independent t test kruskal-wallis ANOVA ----------- Correct Answer ---------- Independent t test The interpretation of a p-value varies depends on what statistical test was used to obtain the p- value ----------- Correct Answer ---------- False When comparing ratio level variable that is normally distributed and without outliers in 3 different groups of patients, which statistical test should be used Kruskal-Wallis ANOVA Friedman test Chi-square test One-way ANOVA ----------- Correct Answer ---------- One-way ANOVA A Pearson correlation coefficient is 0.04. This correlation indicates that there is A statistically significant relationship between the variables A moderate, positive relationship between the variables A strong relationship between the variables A very weak relationship between the variables ----------- Correct Answer ---------- A very weak relationship between the variables A researcher is comparing the outcome variable of cost in US dollars in 3 independent groups.
False When testing for a relationship between 2 independent, nominal variables, the best test to use would be a/an Independent t-test Pearson correlation coefficient Chi-square test Spearman correlation coefficient ----------- Correct Answer ---------- Chi-square Epidemiology is the study of the _____ and _____ of heath-related states or events in specified _____, and the application of this knowledge to the control of health _____. ------------ Correct Answer ----------- distribution determinants populations problems _____ refers to systematic surveillance, observation, experimentation and use of a scientific approach ------------ Correct Answer ----------- Study _____ refers to the frequency and pattern of health related states and events. ------------ Correct Answer ----------- Distribution ______ refer to the physical, biological, social, cultural, economic and behavioral factors that influence health. ------------ Correct Answer ----------- Determinants The goal of _____ is to identify factors associated with the development of disease and injury as well as factors that prevent illness and promote wellness ------------ Correct Answer ----------- epidemiology Epidemiology focuses on ______ health rather than the individual. ------------ Correct Answer --- -------- population The first four core epidemiological functions, ______, _____, ______, and _____, are used to _____ the distribution and determinants of health, as well as evaluate the ______ of health interventions and services. ------------ Correct Answer ----------- SAFE: surveillance analytic studies field investigations evaluation describe/identify efficacy The last two core epidemiological concepts are ____ and ____. ------------ Correct Answer ------- ---- policy linkages
Epidemiological measurements focus on the _____ (frequency and pattern) and _____ (factors and causes) of health issues. ------------ Correct Answer ----------- distribution determinants ______ epidemiology describes the frequency and pattern of data. Frequency is the number of events, and pattern= 3Ws ____, ____, and ____. ------------ Correct Answer ----------- Descriptive who where when _____ epidemiology quantifies the association between exposures and outcomes to determine causal relationships. ------------ Correct Answer ----------- Analytic Descriptive epi is to analytic epi like _____ is to _____. ------------ Correct Answer ----------- distribution determinants Height and weight are examples of ____ measurements, heart rate and blood pressure are examples of ____ measurements, and glucose and cholesterol are examples of ____ measurements. ------------ Correct Answer ----------- anthropometric physiologic biochemical Number of hospital acquired infection would be a performance _____ for the hospital. ------------ Correct Answer ----------- metric Variables are defined according to ____ and ____. ------------ Correct Answer ----------- concept (what it is) operation (how and with what it is measured) The _____ variable is the one manipulated by the researcher, and the ____ variable is the one affected (outcome variable). ------------ Correct Answer ----------- independent dependent There can only be one _____ variable. ------------ Correct Answer ----------- independent T/F: There can only be one dependent variable. ------------ Correct Answer ----------- False (independent) ______ is about the precision of measurements. ------------ Correct Answer ----------- Reliability _____ means that the measurement can be repeated or reproduced. It does not mean that it is _____. ------------ Correct Answer ----------- Reliability accurate
Match the following variables to the correct level of measurement. Temperature in Fahrenheit Disease status (present or absent) Weight in ounces Race, self-reported Quality of life, on a scale of 1 to 5 Hemoglobin A1C Time in minutes Level of Education (< High School, High School Graduate, Some College, College Graduate) Oxygen saturation in percent Blood type A. Interval B. Nominal C. Ratio D. Ordinal ------------ Correct Answer ----------- A-Temperature in Fahrenheit B-Disease status (present or absent) C-Weight in ounces B-Race, self-reported D-Quality of life, on a scale of 1 to 5 C-Hemoglobin A1C C-Time in minutes D-Level of Education (< High School, High School Graduate, Some College, College Graduate) C-Oxygen saturation in percent B-Blood type T/F: A conceptual definition defines how a variable will be measured, and includes the equipment and procedures that are used in the measurement. ------------ Correct Answer ----------- False (Operational) Testing a new piece of equipment to ensure that the equipment consistently provides that same measurement when the same variable is measured multiple times is an example of: A. Accuracy B. Validity C. Reliability D. All of the above ------------ Correct Answer ----------- C. Reliability T/F: The validity of a weight measurement obtained with an electronic scale refers to the repeatability of the measurement. ------------ Correct Answer ----------- False (reliability) T/F: A student is planning on conducting a quality improvement project on a unit in the university hospital where the student is enrolled. Since the project is required by the university and the university owns the hospital, the student does not need to obtain additional permission
for the project. ------------ Correct Answer ----------- False. The student needs institutional approval from the hospital. A nurse practitioner student is completing his final practicum in the outpatient clinic of the health care organization that is part of the university. As a part of the course requirements for the final term, the student must complete a quality improvement project. The student decides to examine whether the staff routinely assess vaccination status for healthy adults. Since this is a quality improvement project for the clinic and a course requirement for the student, does the student need any additional approvals to review patient records for this project? A. No, only research projects require approval. B. Yes, the student needs to obtain appropriate permission to examine the data. C. No, this is a required student project and it is being conducted at the student's own university medical center. D. Yes, the student's project must undergo a full IRB review and approval. ------------ Correct Answer ----------- B. Yes, the student needs to obtain appropriate permission to examine the data. Research requires approval from the _____. ------------ Correct Answer ----------- IRB (Institutional Review Board) T/F: Data integrity refers to the accuracy of the data. ------------ Correct Answer ----------- True. A data plan must address: A. How the data will be measured B. How the data will be recorded C. How the data will be entered into an electronic file D. How the data will be examined for accuracy E. All of the above ------------ Correct Answer ----------- E. All of the above Data is organized into a ____ ____, also known as a rectangular file. ------------ Correct Answer - ---------- line list According to the basic structure of a data file, the (rows/columns) contain the records, observations, or cases, and the (rows/columns) contain the variables. ------------ Correct Answer - ---------- rows columns T/F: The first column of a data file usually contains a personal identifier. ------------ Correct Answer ----------- False. Non-personal record identifier (01, 02, 03, etc. or randomly generated number or letter combination) T/F: The identifier is not a variable and is not analyzed or described. ------------ Correct Answer - ---------- True. It is arbitrary. What are the first two steps of data analysis? ------------ Correct Answer ----------- 1. Enter clean,
The decision of whether to use the mean or median is based on the _____ and the _____. --------- --- Correct Answer ----------- shape of distribution presence of outliers If the distribution is normally distributed AND there are no outliers, which measure of central location is reported? ------------ Correct Answer ----------- mean If the distribution is normally distributed OR there is one or more outliers, which measure of central location is reported? ------------ Correct Answer ----------- median What are the seven measures of spread? ------------ Correct Answer ----------- 1. statistical range
- epidemiological range
- percentiles
- quartiles
- interquartile range
- standard deviation
- coefficient of variation What is the statistical range? ------------ Correct Answer ----------- Difference between largest and smallest value, i.e. (50-30)= 20 How is the epidemiological range reported? ------------ Correct Answer ----------- As two numbers: the largest and smallest values, i.e. 50, 30 What are the commonly reported quartiles? ------------ Correct Answer ----------- Q1 and Q What is the IQR? ------------ Correct Answer ----------- Q3 minus Q1 (reported as one value, best practice to include Q1 and Q3) What is Q2? ------------ Correct Answer ----------- the median The standard deviation is the measure of the average distance between the _____ and the _____. ------------ Correct Answer ----------- observations mean 95% of the observations fall within... ------------ Correct Answer ----------- 2 standard deviations of the mean 68% of observations fall within.... ------------ Correct Answer ----------- 1 standard deviation of the mean Which measure of spread identifies the individual measure of spread in the data set? ------------ Correct Answer ----------- Standard deviation T/F: Measures of central location and spread are used for both categorical and continuous data. -- ---------- Correct Answer ----------- False. Only continuous.
The maximum value is the ____th percentile. ------------ Correct Answer ----------- 100th (100% of values fall at or below it) What does a Z score tell you? ------------ Correct Answer ----------- How many standard deviations away from the mean a value is. If it is positive, it is above. It is negative, it is below. What are the three most commonly reported measures of spread? ------------ Correct Answer ----- ------ 1. SD
- IQR
- Epidemiological range T/F: The measure of central location determines which measure of spread should be reported. --- --------- Correct Answer ----------- True If you report the mean, which measures of spread should be reported? ------------ Correct Answer ----------- standard deviation and epidemiological range If you report the median, which measures of spread should be reported? ------------ Correct Answer ----------- IQR (also best practice to report Q1, Q3) and epidemiological range (max and min) Which graph displays the most information? ------------ Correct Answer ----------- Box and whisker. It depicts the overall and central distribution, quartiles, and outliers. What is the statistical summary data to run for continuous data? ------------ Correct Answer ------- ---- n, mean, median, mode, SD, (statistical) range, IQR, Q1, Q3, min, max Which element of a box and whisker plot shows outliers? ------------ Correct Answer ----------- Tukey fences For continuous data, if there are no outliers, do you need to perform a normality test? ------------ Correct Answer ----------- Yes. The data must have no outliers AND be normally distributed in order to determine that you need to report the mean rather than the median. What normality test do you use for univariate continuous data? ------------ Correct Answer -------- --- Shapiro-Wilke Standard summary for continuous variables.... ------------ Correct Answer ----------- n mean or median if mean, SD and epidemiological range; if median, IQR and epidemiological range (best practice also Q1 and Q3) What type of graphic display would be the best for a variable measured at the ordinal level? A. Bar chart
