1. Intro to Stats and Collecting Data

Identify the sampling technique used, and discuss potential sources of bias (if any). Explain.

A student asks 18 friends to participate in a psychology experiment.

The Memory Drug? Researchers wanted to evaluate whether ginkgo, an over-the-counter herb marketed as enhancing memory, improves memory in elderly adults as measured by objective tests. To do this, they recruited 98 men and 132 women older than 60 years and in good health. Participants were randomly assigned to receive ginkgo, 40 milligrams (mg) 3 times per day, or a matching placebo. The measure of memory improvement was determined by a standardized test of learning and memory. After 6 weeks of treatment, the data indicated that ginkgo did not increase performance on standard tests of learning, memory, attention, and concentration. These data suggest that, when taken following the manufacturer’s instructions, ginkgo provides no measurable increase in memory or related cognitive function to adults with healthy cognitive function.

What is the factor that is set to predetermined levels? What are the treatments?

Which of the following best describes the term $\mathrm{response} \mathrm{variable}$ in statistics?

Sugar Listed below are measured weights (mg) of sugar in Domino packets labelled as containing 3500 mg (or 3.5 g).

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d. Given that the weights are from Domino sugar packets selected from a much larger population, are the weights a sample or a population?

Which of the following is an example of statistical quality control?

Which of the following best describes a statistical question?

In the context of Intro to Stats, what is the first step when creating a line plot?

Which of the following is a discrete quantitative set of data?

In Exercises 9–20, identify which of these types of sampling is used: random, systematic, convenience, stratified, or cluster.

Criminology Researchers randomly selected 50 convicted felons from each category of burglary, auto theft, and assault.

Which of the following levels of measurement can be used for qualitative data?

In the context of an introductory statistics course, if authors use $\mathrm{statistics}$ in an excerpt, what is the most likely purpose of including those $\mathrm{statistics}$?

In Exercises 29–32, indicate whether the observational study used is cross-sectional, retrospective, or prospective.

Marijuana Study Researchers from the National Institutes of Health want to determine the current rates of marijuana consumption among adults living in states that have legalized the use of marijuana. They conduct a survey of 500 adults in those states.

Which of the following is an example of time series data?