statistics psych help (Please answer any that you can) thanks

On the basis of her newly developed technique, a student believes she can reduce the amount of time schizophrenics spend in an institution. As a director of training at a nearby institution, you agree to let her try her method with 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.

What are the null and alternative hypotheses being tested?

H0 = 



H1 = 

Using the obtained probability method of determining significance:

b. State your decision rules

c. Give the mean of the sampling distribution of the mean under the null hypothesis.

d. Give the standard error of the mean of the sampling distribution of the mean under the null hypothesis.

e. What is zobt?

f. What is pobt?

g. Compare your pobt to your decision rules and make a decision

Using the critical value method of determining significance:

h. State your critical value

I. State your decision rules

j. Compare your zobt (from part e.) to your decision rules and make a decision k. Did you come to the same decision using both methods?

l. State your conclusion

m. If you made an error, what type of error did you make?

n. To what population do these results apply?