Conducting a Z Test

39027A researcher predicts that watching a film on institutionalization will change students attitude about mental illness patients. The researcher randomly select a class of 36 students, shows them the film, and give them a questionnaire about their attitudes. The mean score on the questionnaire is 70. The score for people in general on this questionnaire is 75, with a deviation of 12. Using the five steps of hypothesis testing, and the 5% significance level (i.e. alpha = .05), does showing the film changes students attitude towards the chronically mentally ill ? What does it mean to set alpha at .05? What is your null hypothesis? What is your alternative hypothesis? Is this a one-tailed or two-tailed hypothesis? What is the critical Z? Calculate the obtained Z ? Do you reject or fail to reject the null hypothesis ? State what you have found in words