Adult tickets to the fall play cost $8 and student tickets cost $4. the drama class sold 30 more adult tickets than student tickets to the fall play. if the class collected $840 from ticket sales, how many adult tickets were sold?

For a science project, a high school research team conducted a survey of local air temperatures. based on the results of the survey, the found that the average temperatures were around 10 degrees higher than expected. this result was wrong. the trouble with the survey was that most of the locations were exposed to direct sunlight and located over asphalt or sand, which resulted in higher temperatures than normal. this is a classic example of an error in which phase of inferential statistics?