Ichiro’s mother is trying to teach him how to catch a ball. as the ball approaches ichiro, it takes up more and more space on ichiro’s retinas. ichiro perceives the change in size to mean that the ball is getting closer to him rather than perceiving it to mean the ball is getting larger. which term does the best job of describing this phenomenon?

Population parameters are difficult to calculate due to

How are the three economic questions answered in a traditional economic system

The authors of the paper "fudging the numbers: distributing chocolate influences student evaluations of an undergraduate course"† carried out a study to see if events unrelated to an undergraduate course could affect student evaluations. students enrolled in statistics courses taught by the same instructor participated in the study. all students attended the same lectures and one of six discussion sections that met once a week. at the end of the course, the researchers chose three of the discussion sections to be the "chocolate group." students in these three sections were offered chocolate prior to having them fill out course evaluations. students in the other three sections were not offered chocolate. the researchers concluded that "overall, students offered chocolate gave more positive evaluations than students not offered chocolate." indicate whether the study is an observational study or an experiment. give a brief explanation for your choice.