Exam 1: Introduction to Statistics

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

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

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

Identify which type of sampling is used. A research team wants to study the demographics of college students in the U.S. using proportionate samples of students in majors reflecting actual U.S. percentages.

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

Why is cluster sampling frequently used in practice?

Explain why using self-reported data instead of measured data is a potential pitfall in data collection. Be sure to include an example.

Identify the sample and population. Also, determine whether the sample is likely to be representative of the population. A study is interested in whether men and women are equally likely to vote Democratic, Republican or Independent or not vote in a presidential election. Results were polled through a popular news website.

Explain what is meant by the term "confounding," and give an example of an experiment in which confounding is likely to be a problem.

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.

Why do you think that cluster sampling is frequently used in practice?_

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.

A ______________ is the complete collection of all measurements or data collected, whereas, a _____________ is a subcollection of members selected from the complete collection.

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

Determine whether the given description corresponds to an observational study or an experiment. A political pollster reports that his candidate has a 10% lead in the polls with 10% undecided.

A psychology student wishes to investigate differences in political opinions between business majors and political science majors at her college. She randomly selects 100 students from the 260 business majors and 100 students from the 180 political science majors. Does this Sampling plan result in a random sample? Simple random sample? Explain.

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?

Given the data in the table, what issue can be addressed by conducting a statistical analysis of the values? Amounts of Saturated Fat (in grams) in Two-Once Regular and Low-Fat Muffins Regular 4.5 3.5 3.7 5.2 4.9 3.9 Low-Fat 1.2 2.1 2.2 1.8 1.6 2.2

A _______________ is the collection of data from every member of the population

Determine which of the four levels of measurement is most appropriate. Students' grades, A, B, or C, on a test.