Exam 1: Introduction to Statistics

The temperature of a cup of coffee is 67.3°F.

Identify the type of observational study (cross-sectional, retrospective, prospective). -Explain the difference between stratified and cluster sampling.

Why is cluster sampling frequently used in practice?

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

Identify which type of sampling is used. To avoid working late, a quality control analyst simply inspects the first 100 items produced in a day.

Alex and Juana went on a 25-mile canoe trip with their class. On the first day they traveled 17 miles. What percent of the total distance did they canoe?

An advertisement for a heating pad says that it can reduce back pain by 200%. What is wrong with this statement?

Determine whether the given value is a statistic or a parameter. After taking the first exam, 15 of the students dropped the class.

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. Does the conclusion that the techniq 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 ue is effective appear to be supported with statistical significance? Does the conclusion that the technique is effective appear to have practical significance?

Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience. -A market researcher selects 500 drivers under 30 years of age and 500 drivers over 30 years of age.

A researcher investigated whether following a vegetarian diet could help to reduce blood pressure. For a sample of 85 people who followed a vegetarian diet for 4 months, the mean systolic blood pressure was 124 mmHg and for a sample of 75 people who followed a nonvegetarian diet for 4 months, the mean systolic blood pressure was 138 mmHg. Methods of statistics show that if a vegetarian diet had no effect on blood pressure, there would be less than 1 chance in a 100 of getting these results. Does the result have statistical significance? Why or why not? Does the result have practical significance?

On a test, 74% of the questions are answered correctly. If 111 questions are correct, how many questions are on the test?

Nationalities of survey respondents.

In a random sample of 160 women, 78% favored stricter gun control laws. In a random sample of 220 men, 61% favored stricter gun control laws. Is there statistically significant evidence that a larger proportion of women than men favor stricter gun control laws?

Salaries of college professors.

Identify which of these types of sampling is used: random, stratified, systematic, cluster, convenience. -An education researcher randomly selects 48 middle schools and interviews all the teachers at each school.

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.

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

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

Identify the type of observational study (cross-sectional, retrospective, prospective). -A town obtains current employment data by polling 10,000 of its citizens this month.