Which graph shows data whose r-value is most likely closest to 1?

A graph shows both axes unnumbered. Points show a downward trend.
A graph shows both axes unnumbered. Points show an upward trend.
A graph shows both axes unnumbered. Points show a downward trend.
A graph shows both axes unnumbered. Points are scattered all over the graph.

How can constraints be used to model a real-world situation?

Alexandra drove from michigan to colorado to visit her friend. the speed limit on the highway is 70 miles per hour. if alexandra's combined driving time for the trip was 14 hours how many miles did alejandra drive?

Stu and ambrose are working together on a study of whether diet is related to students' mental health. first, they randomly select 10 students from the student center and 10 students from the office of counseling and psychological services. then, they ask students to rate their diet in terms of healthiness on a scale of 1-100 before completing a 20-item mental health survey. a) name one of the constructs being studied b) how was the construct you named above operationally defined in this experiment? e) was the variable you described above their independent variable, their dependent variable, or a controlled variable? d) what is a confounding variable? what is a potential confound in this study?