What are the two basic steps used when analyzing data?

What are the assumptions underlying the use of the z test?

What are the characteristics of the sampling distribution of the mean?

Is it reasonable to consider a sample of 40 scores with to be a random sample from a population of scores that is normally distributed, with μ = 60 and σ = 10? Useα = 0.052 tail in making your decision.

On the basis of her newly developed technique, a student believes she can reduce the amount of time schizophrenics spend in an institution. As director of training at a nearby institution, you agree to let her try her method on 20 schizophrenics, randomly sampled from your institution. The mean duration that schizophrenics stay at your institution is 85 weeks, with a standard deviation of 15 weeks. The scores are normally distributed. The results of the experiment show that the patients treated by the student stay a mean duration of 78 weeks, with a standard deviation of 20 weeks.

A. What is the alternative hypothesis? In this case, assume a nondirectional hypothesis is appropriate because there are insufficient theoretical and empirical bases to warrant a directional hypothesis.

B. What is the null hypothesis?

C. What do you conclude about the student’s technique? Use α = 0.052 tail