Question

answer the questions below.
(a) a financial magazine conducted a survey. it showed that a person with more years of education tends to have a higher salary. what is likely true?
there is no correlation between years of education and salary.
there is a correlation between years of education and salary. there may or may not be causation. further studies would have to be done to determine this.
there is a correlation between years of education and salary. there is probably also causation. this is because there is an increase in salary with an increase in the years of education.
(b) a grocery store collected sales data. it found that a change in price does not imply that people will buy more or less milk. what can we determine from this information?
there is no correlation between price and amount of milk bought.
there is a correlation between price and amount of milk bought. however, there is no causation. this is because there is likely a decrease in the amount of milk bought with an increase in the price.
there is a correlation between price and amount of milk bought. there may or may not be causation. further studies would have to be done to determine this.
(c) mr. patterson studied his students history test scores and tv habits. he found that students who watched less tv tended to earn higher scores on the test. what conclusion should he make?
there is no correlation between test score and amount of tv watched.
there is a correlation between test score and amount of tv watched. there is probably also causation. this is because there is an increase in a students test score with a decrease in the amount of tv watched.
there is a correlation between test score and amount of tv watched. there may or may not be causation. further studies would have to be done to determine this.

Explanation:

Part (a)

The survey shows a tendency: more education years → higher salary. Correlation means a relationship. Causation (education causes higher salary) is plausible here because education often provides skills/knowledge that lead to better - paying jobs, but we still need to be cautious. The first option is wrong as there is a relationship. The second option is too tentative; the relationship here has a strong causal implication. So the third option is correct: "There is a correlation between years of education and salary. There is probably also causation. This is because there is an increase in salary with an increase in the years of education."

The data shows that price change doesn't imply change in milk bought. Correlation is a relationship between two variables. If price change doesn't affect the amount bought, there's no relationship (correlation) between price and amount of milk bought. The second and third options assume a correlation exists, which is wrong. So the first option is correct: "There is no correlation between price and amount of milk bought."

The study shows a tendency: less TV watched → higher test scores. This means there is a correlation (relationship) between TV watching and test scores. But causation (watching less TV causes higher scores) isn't certain yet (maybe other factors like study time are involved). The first option is wrong as a relationship exists. The second option is too hasty in assuming causation. So the third option is correct: "There is a correlation between test score and amount of TV watched. There may or may not be causation. Further studies would have to be done to determine this."

Answer:

There is a correlation between years of education and salary. There is probably also causation. This is because there is an increase in salary with an increase in the years of education.

Part (b)