WGU C431 Healthcare Statistics extra quiz questions and correct answers 2022

WGU C431 Healthcare Statistics extra quiz questions and correct answers 2022When the subject in a study are not representative of the population, this is a limitation referred to as ________ A) Measurement Error B) Probability Bias C) Sampling Bias D) Recall Bias E) Publication Bias C Sampling Bias _______________ is when the determination of whether to publish a study is based on factors other than the quality of the research and the relevance of its findings A) Measurement Bias B) Publication Bias C) Sampling Bias D) Representative Bias E) Lack of clinical significance bias B Publication Bias Researchers strive to remain unbiased, honest, and precise when making decisions regarding the planning, conducting, and reporting of a quantitative and qualitative study. The previous statement defines A. Validity B. Reliability C. Objectivity D. Credibility E. Dependability C Objectivity Identify the characteristic of research design that relates to the degree to which the outcomes of the study can be attributed to the interventions. A. Inter-rater reliability B. Intra-rater reliability C. External validity D. Internal validity E. Randomization C External Validity What variables interfere with the intended purpose of the investigation by introducing error to the study? A. Extraneous variable B. Intervening variable C. Dependent variable D. Independent variable E. A and B F. C and D E) A & B - Extraneous and Intervening Variable What is the procedure called for assigning subjects to intervention groups (placebo group, control group, experimental group.)? A. Inter-rater reliability B. Intra-rater reliability C. External validity D. Internal validity E. Randomization C External Validity Identify the type of evidence that combines the statistically analyses of multiple independently conducted studies. A. Meta-analysis B. RCT C. Systematic review D. Cohort study E. Cross-over study A) Meta-analysis A power analysis is calculated to A. Determine the sample size at the beginning of the study B. Take into consideration a 20% drop out rate C. Ensure the sample size was large enough to detect differences in the treatment and comparison group after data collection D. A and B E. All of the above C) Ensure the sample size was large enough to detect differences in the treatment and comparison group after data collection . ___ is a statistical procedure that determines the probability that the effect of interest will be observed when it occurs. It is utilized in a sample size calculation in order to determine the necessary number of subjects needed in order to attain the desired level of power. A. Effect size B. Degrees of freedom C. One-sample t-test D. Regression analysis E. A power calculation E) Power Calculation ___ is a comparison of a statistic, such as a mean or a proportion, between two or more groups. A. Effect size B. Power C. A test for differences D. Correlation E. A test statistics C) A test of differences . ___ is the accuracy of measurements. It is the degree to which an instrument measures what is it supposed to measure. A. Pearson's Product Moment Correlation Coefficient B. Factor analysis C. Validity D. Pre-clinical trial E. Confidence interval C) Validity In a study comparing acupuncture, counseling, and usual medication care for treatment of depression, the researchers determined that an improvement of 0.32 (32%) on the Personal Health Questionnaire (PHQ-9) was necessary in order for the intervention to make a meaningful difference. What type of statistic is 0.32? A. Alpha B. Power C. Effect Size D. Confidence Interval E. Sample Size C) Effect Size 00:02 01:17 Researchers selected α 0.01 for a study comparing two different diagnostic procedures for ankle injuries (X-ray vs. history/physical exam). What is the chance that the resulting test statistic will represent normal variability? A. 0% B. 1% C. 10% D. 99% E. Cannot be determined with the information provided B) 1% Alpha is ___. A. the probability a Type I error B. the size of a sample C. the effect size is a sample size calculation D. the level of power E. incorrectly failing to reject the null hypothesis A) the probability a Type 1 error Researchers performed a study comparing Treatment A and Treatment B. The calculations they performed indicated that Treatment A was significantly better than Treatment B. However, they later discovered an error in data collection and determined that Treatment A and Treatment B were, in fact, equivalent. What mistake did they make? A. There was no mistake made. B. They incorrectly rejected the null hypothesis, which is a Type I error. C. They incorrectly rejected the null hypothesis, which is a Type II error. D. They incorrectly failed to reject the null hypothesis, which is a Type I error. E. They incorrectly failed to reject the null hypothesis, which is a Type II error. B) They incorrectly rejected the null hypothesis, which is a Type I error. In a normal distribution ___ of all normally occurring results will fall below the median. A. 25% B. 67% C. 5% D. 1% E. 50% E) 50% Approximately ___ of observations in a normal distribution are more than two standard deviations below the mean. A. 5% B. 1% C. 2.5% D. 10% E. 50% C) 2.5% In a hypothetical study, researchers have a normally distributed sample and a normally distributed set of data derived from the sample. The study is comparing the amount of weight lost among this group of subjects with the amount of weight loss reported by the National Child Fitness Program (NCFP). The NCFP reported in a 2011 study that daily exercise of 30 minutes at target heart rate would produce a 2% average weight loss (± 0.5%) among obese, but otherwise healthy children between ages 9 and 12 years. Based on the scale of the data, the shape of the distribution, and the type of comparison to be made, which statistical test should be used? A. Chi-square B. One-sample t-test C. Factor analysis D. ANOVA E. Correlation coefficient B) One-sample t-test In a hypothetical study on weight loss among otherwise healthy, but obese children between 9 and 12 years old, researchers compared kickball, basketball, soccer, flag football, and capture-the-flag. The amount of weight loss associated with each type of activity was compared to the average amount of weight loss reported by the NCFP (National Child Fitness Program). In the NCFP 2% average weight loss (± 0.5%) was achieved by having children jog on a treadmill for 30 minutes at their target heart rate. The researchers in the present study were interested in identifying physical education activities that achieved the same or more weight loss compared to the treadmill. The variable of weight was found to be normally distributed among all intervention groups. In the basketball group the average amount of weight loss after 4 weeks was 2 pounds, with a standard deviation of 0.5 pounds. What percentage of the basketball group lost between 1.5 and 2.5 pounds? A. approximately 68% B. approximately 50% C. approximately 95% D. approximately 99% E. approximately 34% A. approximately 68% A p-value of 0.023 is ___ standard deviation(s) above or below the mean. A. less than one B. close to two C. more than three D. exactly four E. five B. close to two In a hypothetical study of weight loss among overweight but otherwise healthy 9-12 year olds, the average percentage weight loss among the group that played basketball was 2% (± 0.5%). Which of the following values is most likely to be a true population parameter for weight loss, based on a 95% confidence interval for the test statistic? A. 0.01% weight loss B. 5% weight loss C. 0% weight loss D. 3% weight loss E. 2.3% weight loss E. 2.3% weight loss