Studies Surveys Experiments

Four groups of randomly selected people are assigned a different diet. After six months, the blood pressures of each group are compared.

• Observational Study

• Experiment

Disneyland often surveys its guests as they exit a restaurant during their visit. The surveyor stands at the restaurant exit, counts the number of people leaving, and surveys every 25th guest.

This is a form of:

• Simple Random Sample

• Systematic Sampling

• Voluntary Response

• Stratified Sampling

In a survey of a sample of high school students, 43% said that their mother has taught them the most about managing money.

• parameter

• statistic

A poll is taken from 100 seniors in a high school where the senior class has 575 students. This is an example of a ______________.

• Sample

• Population

a controlled study in which the researcher attempts to understand cause-and-effect relationships by assigning subjects to groups and deciding which treatments each group receives

• survey

• observational study

• experiment

In a certain school, students can choose whether to eat in the school’s cafeteria. A reporter working for the school’s newspaper polled students on their reactions to changes in the menu at the cafeteria. For each student leaving the cafeteria in one 20-minute time period, the reporter used a die to determine whether to stop the student and ask how he or she felt about the new menu. In the reporter’s article it was stated that a random sample of the students showed that 23% of the school’s student population was happy with the new menu. Which of the following statements is true?

• Because each student leaving the cafeteria was randomly selected and could choose to answer or not, this is a random sample of the student population, and the 23% is an accurate measurement of the school population’s view of the new menu.

• Because students self-selected whether to eat in the cafeteria, the sampling method might be biased and the sample might not be representative of all students in the school.

• The survey would have been more effective if the reporter had collected the data in one 10-minute time period rather than in one 20-minute time period.

• The survey would have been more effective if students who cared about the food could have called the reporter to tell how they felt about the new menu, so that only students with opinions on the subject would have been surveyed.

• Because no treatment was imposed on the students eating in the cafeteria, one cannot make any conclusions about the new menu.

You want to see if students who have a 4.0 grade point average study more than those who do not.

• survey

• observational study

• experiment

A large company wants to conduct a survey to determine the proportion of its male employees who practice yoga on a daily basis. Two of its regional offices are chosen at random and all of the male employees at each office are surveyed. The plan is an example of which type of sampling?

• Cluster

• Convenience

• Simple random

• Stratified random

• Systematic

The part of the population that the data actually comes from is called the:

• outlier

• sample

• friendly

True or False. Surveys and experiments are ways that statisticians collect data to analyze.

• true

• false