Which client statement best indicates an understanding of using emtricitabine and tenofovir disoproxil fumarate (Truvada) for pre-exposure prophylaxis (PrEP)?

In a public health study on the effects of consumption of fruits and vegetables on psychological well-being in young adults, participants were randomly assigned to three groups: (1) diet-as-usual, (2) an ecological momentary intervention involving text message reminders to increase their fruits and vegetable consumption plus a voucher to purchase them, or (3) a fruit and vegetable intervention in which participants were given two additional daily servings of fresh fruits and vegetables to consume on top of their normal diet.  Participants were asked to take a nightly survey on their smartphones. Participants were student volunteers at the University of Otago, New Zealand. At the end of the 14-day study, only participants in the third group showed improvements to their psychological well-being across the 14-days relative to the other groups. (Conner et al., 2017) What is the explanatory variable? 

A researcher is interested in seeing if there is an association between whether or not an individual uses a smart phone right before bed and how well an individual sleeps. Participants in the study report whether or not they used a smart phone before bed and then rate their quality of sleep as either “poor,” “average,” or  “good.” poor average good I use a smart phone before bed 27 15 10 I don’t use a smart phone before bed 14 17 23 The researcher concludes at the end of the study that there is an association between the two variables-whether the quality of sleep was poor and using smartphone before bed-after comparing two statistics _________ and __________. 

Which of the following study designs would give you the true value of the parameter?

Suppose you have a data set with the following five-number summary: Minimum = 26, Q1 = 32, Median = 34, Q3 = 38, Maximum = 58. What is the upper cutoff point for potential outliers? (By upper cutoff point, we mean the number such that anything greater than it is an outlier). 

Below is shown a boxplot of ages of participants in a study. What statistics do you recommend for the center and spread of these ages?  Why?  

The CDC recently started a push to make sure all Americans know that alcohol can cause cancer.  Below is a graph of the ages at which an alcohol associated cancer was first found. Which of the following things do we expect to be true about the age distribution among alcoholrelated cancers?https://gis.cdc.gov/Cancer/USCS/#/RiskFactors/  

Which of the following is a false property of the standard deviation?

A researcher wants to determine if a new exercise program helps people lose weight. She recruits over 1200 subjects (her statistician determined this number from sample size calculations) and randomly assigns them to either participate in the new exercise program or no exercise program. She tells those in the new program group to exercise 3 times a week and tells those in the no exercise group that they should not exercise for the duration of the study. Based on this information, which of the following principles of experimental design is not presented in this study?

Of the following graphs, which has the SMALLEST standard deviation?  All data was randomly generated with a sample size of n = 50, and all values of all the data are between 0 and 10.  Be aware that the graphs are out of order on your answers!