A researcher interested in habits of smokers collected data on the number of cigarettes smoked in one month and the number of time they visited church that month. The correlation for these two variables ended up being -0.74. If a smoker who had never been to church started attending church regularly what should we expect to happen?
Choose one answer.
The smoker will not attend church for very long.
We can not conclude anything about the future habits of the smoker.
The smoker will smoke less cigarettes.
The smoker will smoke more cigarettes.
A crop scientist is conducting research with a drought resistant corn hybrid. She is interested in determining if using fertilizer X will increase yield. She prepares 20 single acre plots and randomly assigns 10 to have normal soil while the other 10 are planted with fertilizer X. The resulting average yield for each group of 10 plots was recorded.
The response variable is the average yield for each group of 10 plots.
This is best described as an observational study.
The response variable is whether the corn plants had fertilizer X or not.
The explanatory variable is whether the corn plants had fertilizer X or not.
This study is best described as an experiment.
The explanatory variable is the average yield for each group of 10 plots.