The test statistic (z) is -1.30 what is the rejection region? (what is z> ? and what is z<?

Question

An experimenter has prepared a drug-dose level that he claims will induce sleep for at least 70% of people suffering from insomnia. After examining the dosage we feel that his claims regarding the effectiveness of his dosage are too high. In an attempt to disprove his claim, we administer his prescribed dosage to 70 insomniacs and observe that 44 of them have had sleep induced by the drug dose. Is there enough evidence to refute his claim at the 5% level of significance?

Answer 1

Ho: P≥0.7

Ha: P<0.7

Rejection Region at ∝=0.05 is Z<-1.645

It's a one sided test. There is only one rejection region. In this case we would fail to reject Ho. There is not convicing evidence that the proprotion of insomniacs that had sleep induced by this dosage is less than 0.7.

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