AP Statistics Designing Experiments

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.

When p-value is greater than alpha we:

• Accept Ho

• Accept Ha

• Fail to reject Ho

• Reject Ho

• A
• B
• C
• D

What type of study is described? A gym tries out a new weightlifting method to see if it will build muscle for their customers faster than their current method.

• Sample Survey

• Experiment

• Observational Study

Does listening to classical music while studying increase test scores?

• Survey

• Observational study

• Experimental study

• A
• B
• C
• D

• The slope decreased and the r² increased.
• The slope increased and the r² decreased.
• The slope decreased but r² remained the same.
• Both slope and r² remained the same.

What's the appropriate interpretation of the slope of the regression line?

• For every additional 0.61 hours of growth, the culture is predicted to weight 1 more gram.

• For every additional hour of growth, the culture is predicted to weigh 0.61 more grams.

• For every additional hour of growth, the logarithm of the culture's weight in grams is predicted to increase by 0.61.

• At the beginning of the experiment, the logarithm of the culture's weight in grams was approximately 0.61 ounces.

• A
• B
• C
• D