Correlations

A researcher determines that the crime rate in a city changes with the win-loss record of the city's pro football team. He concludes that the performance of the team (winning or losing) influences the city's inhabitant's behavior. What error does he make?

• He only looked at criminals, not the general population.

• He doesn't look at other cities, and their team's win/loss ratio

• He incorrectly inferred causation from correlation

• He didn't choose the city inhabitants randomly.

Of the following choices, which coefficient indicates the SMALLEST correlation between two variables?

• -0.66

• -0.05

• 0.09

• .33

Research shows that generally, the higher an incoming college student's high school GPA, the higher the college student's college GPA. Which of the following describes this relationship?

• a normal distribution

• a positive correlation

• a negative correlation

• a skewed distribution

During baseball season, concession stand attendants notice a negative correlation between the home team's score and total sales of food. This means

• The more runs scored by the home team, the lower the total sales of food.

• The more runs scored by the home team, the higher the total sales of food.

• The number of runs scored by the home team has no effect on concession sales.

• The concession stand makes more money when the home team wins

• fans are too disappointed to buy food when the home team is losing

Students with better school attendance show better grades in school. It is easy to assume that attendance leads to better grades, but just as likely, both factors are driven by a third factor. Which statement supports this idea?

• The two factors occur together by chance

• Correlation does not equal causation

• Students who do better in school are more likely to want to attend school, so their attitude about school is the deciding factor.

• Some students are more motivated to do well in school, which leads to better attendance.

• Students have to be present in class to learn the material which leads to good grades.

A superintendent of a school district read and article that stated students who have a higher GPA report getting less sleep than their peers. Which of the following BEST explains these findings.

• A higher GPA causes students to get less sleep

• GPA and sleep are positively correlated

• GPA and sleep are negatively correlated

• There is no correlation between GPA and sleep

• Getting less sleep causes students to have a higher GPA

A researchers wants to find out how well high school attendance predicts student grades. (Read: Not cause grades, just how well the two -attendance and grades- are connected.) Which method should the researchers use?

• A Case study

• An Experiment

• Naturalistic Observation

• Correlational study

Rachel moves in with Joey. Within days of moving in, Joey's refrigerator stops working. Joey believes that it is Rachel's fault that the fridge stopped working because she just moved in. Joey's assumption that Rachel's arrival is related to the refrigerator breaking is an example of

• confirmation bias

• hindsight bias

• judgmental overconfidence

• illusory correlation

• gambler's fallacy