A researcher predicts that watching a film on institutionalization will change students' attitudes about chronically mentally ill patients. The researcher randomly selects a class of 36 students, shows them the film, and gives them a questionnaire about their attitudes. The mean score on the questionnaire for these 36 students is 70. The score for a similar class of students who did not see the film is 75. The standard deviation is 12. Using the five steps of hypothesis testing and the 5% significance level (alpha), does showing the film change students' attitudes towards the chronically mentally ill?
What is your null hypothesis? Alternate hypothesis?
Is this a one-tailed or two-tailed hypothesis?
What is your obtained z?
What is the critical value for z?
Do you reject or fail to reject the null hypothesis?
Calculations for the Z Test of hypothesis for the mean are set-up in the attached Excel file. The null and alternative hypothesis are discussed in the attached Word document with a distribution plot.