All Common Core: 8th Grade Math Resources
Example Questions
Example Question #41 : Statistics & Probability
A school principal conducted a statistical experiment to determine the relationship between and the number of hours spent studying each week. In this study, the principal assigned the number of hours spent studying as the independent variable, and the was assigned as the dependent variable. He plotted his results on a scatter plot. If the results follow a linear relationship, what is a reasonable conclusion that could be found based these results?
An undefined slope
A slope of
A positive slope
A negative slope
A positive slope
We know, from attending school ourselves, that completing homework assignments and studying for quizzes and tests means that we will do better in school than if we didn't do those things. Completing homework and studying for tests takes time outside of school. Normally, the harder you study and the more time you spend studying, the more likely you are to do well in school. If you don't study at all, nor spend anytime completing homework assignments, your school grade will likely be lower than if you had spent time preparing and completing assignments; thus, we can conclude that the more time we spend studying, the higher our will be. As the number of hours studied increases, the will increase; thus, the best fit line will have a positive slope.
Example Question #231 : Data Analysis
A school principal conducted a statistical experiment to determine the relationship between and the number of hours spent studying each week. In this study, the principal assigned the number of hours spent studying as the independent variable, and the was assigned as the dependent variable. The principal drew a line of best fit and found the to be . What does this mean?
Every studying increases a student's
A student who studied hours per week received an average of
Every week of studying increased a student's by
The average student is
A student who studied hours per week received an average of
The question tells us that the hours spent per week studying is the independent variable, or the , and the is the dependent variable, or the
The is when ; thus, when a student spends zero hours studying their average is