Exam 1: Introduction to Statistics

Distinguish between categorical and quantitative data. Give an example of each.

Determine which level of measurement is appropriate. Salaries of college professors.

On a test, 74% of the questions are answered correctly. many questions are on the test?

Correlation does not imply _____________.

"38% of adults in the United States regularly visit a doctor". This conclusion was reached by_ a college student after she had questioned 520 randomly selected members of her college. What is wrong with her conclusion?

The four levels of measurement that are commonly used for classifying data are ratio, ________, ________, and ________.

Researchers collect data by interviewing athletes who have won Olympic gold medals from 1992 to 2016. Identify the type of study.

The good design of experiments includes blinding, _____________, and __________________.

A lawyer surveyed a simple random sample of his colleagues and asked them whether they were left-handed or right-handed. Is this convenience sample likely to provide results typical of all adults in the United States? Do convenience samples in general provide good results?

Identify the type of observational study used. A town obtains current employment data by polling 10,000 of its citizens this month.

Which type of experiment separates subjects into groups that are similar but differ in ways that might affect the outcome of the experiment?

What type of data values are quantitative and the number of values is finite or countable?

A coach uses a new technique in training middle distance runners. The times, in seconds, for 8 different athletes to run 800 meters before and after this training are shown below. Athlete Before 115.2 114 116.4 119.8 110.9 112.4 111.5 117.3 After 112.9 112.7 114 120.6 109.1 109.1 107.9 113.4 Does the conclusion that the technique is effective appear to be supported with statistical significance? Does the conclusion that the technique is effective appear to have practical significance?

A marijuana survey included 1610 responses from a list of approximately 241,500,000 adults in the U.S. from which every 150,000th name was surveyed. Identify which of these types of Sampling is used:

A marketing firm does a survey to find out how many people use a product. Of the one hundred people contacted, fifteen said they use the product. Identify the type of study used.

Explain the difference between stratified and cluster sampling.

Determine whether the given value is a discrete or continuous variable. People are asked to state how many times in the last month they visited their family doctor.

There are many potential pitfalls that can cause problems when analyzing data. Which of these choices are not classified as a potential pitfall?

At a school there are two different math classes for children of the same age._ have different teachers. The school principal is interested in gauging the effectiveness of two different teaching methods and asks each teacher to try one of the methods. At the end of the semester both classes are given the same test and the results are compared. In this experiment, what is the variable of interest? Give some examples of variables which could be confounding variables.

Determine which level of measurement is appropriate. A sample of children's balls are classified from softest to hardest.