What is the null hypothesis of each research? And what statistical test should I choose for each of them and why? 1. A researcher recorded the calories burned by subjects during a 10-minute treadmill exercise. All participants had television located in front them while exercising. In one group, the television played music videos. In a second group, the television played a news channel. In a third group the television was turned off. 2. A study was conducted to investigate the relationship between cigarette smoking and illness. The number of cigarettes smoked daily and the number of days absent from working the last year due to illness were determined for 40 individual employees. 3. A statistics faculty member has noticed a trend that students exhibiting higher levels of anxiety perform worse on their test. The faculty member's goal is to identify, based on anxiety, which students need to be given exercises and support to reduce their anxiety levels so their test performance can improve. To do this the faculty member gives his students an anxiety questionnaire before the final exam, and records the score along with the students final exam score. 4. A cognitive psychologist believes that memory for pictures is superior to memory for words. To test this hypothesis, the psychologist performs an experiment in which students from an introductory psychology class are used as subjects. Eight randomly selected students view 30 slides with nouns printed on them and another group of eight

5. The director of a recreation center on a college campus believes that the more physically active a student is the higher their GPA will be. A random selection of 50 students were selected and were rank ordered by GPA with 1 being the lowest GPA and 50 being the highest. The director then tracked the student's usage of the recreation center for the week, noting how many days in the 7 day period the student visited the center.