NR 716 Week 7 Quiz Statistics

Question

Options

Correct Answer / Explanation

Q1. When testing chemotherapy effectiveness, which is a Type I error?

a) Reporting chemotherapy effective when it is not b) Reporting chemotherapy not effective when it is c) Reporting results inconclusive d) No way to determine

a) Reporting chemotherapy effective when it is not. A Type I error represents a false positive, meaning the null hypothesis is rejected when it is actually true.

Q2. What is an assumption of the Mann Whitney U test?

a) Sample size ≥ 200 b) Scatter “flowerpot” curve c) Independence of observations d) Data are paired

c) Independence of observations. This test assumes that each observation is independent from the others.

Q3. With ratio data, true IV, and 2 groups, which test is most likely used?

a) John’s Relational Test b) Bonjovi’s Test c) Regression Analysis d) Spearman’s Rank Correlation

c) Regression Analysis. Ratio data with independent variables and two groups are best analyzed with regression.

Q4. A histogram measuring income vs education is plotted. What is the distribution?

a) Normal b) Bimodal c) Left Skewed d) Right Skewed

Distribution depends on graph shape. A long right tail indicates right skew, while two peaks show bimodality.

Q5. Which is least useful in understanding data variability?

a) Standard deviation b) Variance c) Mean d) Range

c) Mean. The mean describes central tendency but does not capture variability.

Q6. What are the four levels of measurement?

a) Nominal, Parametric, Linear, Dichotomous b) Parametric, Continuous, Skewed, Interval c) Nominal, Ordinal, Interval, Ratio d) Levels 1–4

c) Nominal, Ordinal, Interval, Ratio. These represent the standard scales of measurement.

Q7. Examples of descriptive statistics are:

a) Mean & Mode b) Pearson’s r & Spearman’s r c) t-test & Bonferroni’s test d) Normal & Bimodal distributions

a) Mean & Mode. These are measures of central tendency used in descriptive statistics.

Q8. The mean is influenced by:

a) Order of data b) Total repeated values c) Individual scores d) Standard deviation

c) Individual scores. Outliers and variations in scores can shift the mean.

Q9. Type II error occurs when…

a) Reject null & reject alternative b) Accept alternative & reject null c) Accept null & reject alternative d) None correct

c) Accept null & reject alternative. This is a false negative, failing to detect an effect when one exists.

Q10. Mean of 6, 4, 1, 9, 3, 8, 3, 5, 10?

a) 5.4 b) 3 c) 6 d) 5

a) 5.4. The sum divided by number of values yields 5.4.

Q11. Assumptions for Pearson’s r include all EXCEPT:

a) Data parametric b) Normal distribution c) Categorical data d) Linear relationship

c) Categorical data. Pearson’s r requires continuous, normally distributed, linear data.

Q12. Which is continuous?

a) Genders b) Class size c) Hair color d) Specialty

b) Class size. Continuous variables take numerical values with a logical order.

Q13. Type I error occurs when researcher…

a) Rejects null & accepts alternative b) Rejects alternative & accepts null c) Accepts null & accepts alternative d) None

a) Rejects null & accepts alternative. This is a false positive.

Q14. Assumption of Spearman’s Rank Correlation:

a) Data parametric b) Normally distributed c) Data at least ordinal d) Categorical/nominal

c) Data at least ordinal. Spearman’s correlation works with ordinal or ranked data.

Q15. Variance tells us:

a) Distance of each data point from mean b) Frequency of values c) Average deviation squared d) Deviation from hypothesis

c) Average deviation squared. Variance measures how spread out data are.

Q16. In chemotherapy testing, which error is more dangerous?

a) Type I b) Type II

b) Type II. Overlooking an effective treatment poses greater risk to patients.

Q17. Assumption for Chi-square test?

a) Blinded collection b) Expected values ≥ 5 c) Samples paired d) Sample ≥ 200

b) Expected values ≥ 5. This ensures valid chi-square calculations.

Q18. Frequency distribution informs us about:

a) Subgroups into quartiles b) How often each value occurs c) General population d) Significance level

b) How often each value occurs. Frequency distribution describes count of occurrences.

Q19. Assumptions for t-test include all EXCEPT:

a) Parametric data b) Normal distribution c) Categorical (nominal) data d) Equality of variances

c) Categorical (nominal) data. A t-test requires continuous parametric data.

Q20. With categorical pre–post data, which test is used?

a) Chi-square b) Bonjovi’s Test c) Milli’s Test d) Pearson’s r

a) Chi-square. It compares frequencies between categories.

Q21. Definition of normal distribution curve?

a) Bell-shaped curve, symmetrical around mean

Correct. Normal distribution is symmetrical with most scores around the mean.

Q22. Data unconnected, distinct, nominal/ordinal (e.g., race, marital status):

a) Monodicot data b) Discrete data c) Measured data d) Random sample data

b) Discrete data. These are categorical or count data.

Q23. Chemotherapy testing—Type II error consequence?

a) Report effective when not b) Report not effective when it is c) Report inconclusive d) No answer

b) Report not effective when it is. This error ignores an effective treatment.

Q24. Four groups, nominal/ordinal data, difference in means → which test?

a) Regression b) Pearson’s r c) Kruskal-Wallis d) Spearman’s r

c) Kruskal-Wallis. It compares multiple groups with nonparametric data.

Q25. Histogram income vs education, distribution?

a) Normal b) Bimodal c) Left Skewed d) Right Skewed

Depends on shape; two peaks indicate bimodal, while skew depends on tail direction.