On the basis of her newly developed technique, a student believes she can reduce the amount ofttimes schizophrenics spend in an institution, A 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

Answer this as you would a FULL hypothesis test on the exam. State ALL your rules, formula, calculations, decision, conclude, etc..