An algebra i test contains 40 questions. some of the questions are worth 4 points each, and some are worth 2 points each. the total test is worth 100 points. let f represent the number of questions worth 4 points and t, the number of questions worth 2 points. solve the system by elimination to find the number of four-point questions on the test.

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?