Smooth Sailing, Inc., conditions future shipments of its products to distributors on their agreement to charge the prices set by Smooth. This is Group of answer choices a barrier to entry. a horizontal restraint. a merger. a vertical restraint.

Martha entered into a contract with terry, an art dealer. according to the contract, terry was to supply 18 th century artifacts to martha for the play she was directing, and martha was ready to pay $50,000 for this. another director needed the same artifacts and was ready to pay $60,000. terry decided not to sell the artifacts to martha. in this case, the court may order terry to:

Arecent poll of 500 residents in a large town found that only 36% were in favor of a proposed referendum to build a new high school. find the margin of error for this poll if we want 95% confidence in our estimate of the percentage of residents in favor of this proposed referendum.

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.