CPH Exam Practice Questions WITH COMPLETE SOLUTIONS

The lengths of stay for six patients were 0, 0, 1, 2, 2, and 16 days. Which is (are) the best measure(s) to summarize these data? A) Mean B) Median C) Median and SD D) Mean and SD E) Median and Range correct answer: E) Median and Range An epidemiologist attempts to predict the weight of an elderly person from demispan. She randomly chooses 70 elderly subjects in a particular geographic area and records their weight and demispan measurements in the form of (x i , y i ) for i = 1...70. Given that the value of the Pearson correlation coefficient is zero, what can be deduced? 1) There is no relation between weight and demispan B) There is an almost perfect relationship between weight and demispan C) There could be some nonlinear relationship between weight and demispan D) There is a strong negative relationship between weight and demispan E) All pairs of values of weight and demispan are practically identical correct answer: C) There could be some nonlinear relationship between weight and demispan Which of the following statistical tests is NOT considered a nonparametric test? A) Kruskal-Wallis Test B) Wilcoxon's rank-sum test C) Tukey's test D) Mann-Whitney test correct answer: C) Tukey's test A researcher is designing a new questionnaire to examine patient stress levels on a scale of 0 to 5. What type of outcome variable is being collected? A) Ratio B) Nominal C) Interval D) Ordinal E) Binary correct answer: B) Ordinal In simple linear regression, what is a method of determining the slope and intercept of the best-fitting line? A) Least squares B) R-square C) Minimum error D) Least Error E) Regression correct answer: A) Least Squares