Developing Null and Alternative Hypotheses!Hypothesis testingcan be used to determine whethera statement about the value of a population parametershould or should not be rejected.!The null hypothesis,denoted byH0,is a tentativeassumption about a population parameter.!The alternative hypothesis, denoted byHa, is theopposite of what is stated in the null hypothesis.!The alternative hypothesis is what the test isattempting to establish.One-tailed(lower-tail)One-tailed(upper-tail)Two-tailedSummary of Forms for Null and AlternativeHypotheses about a Population Mean!The equality part of the hypotheses always appearsin the null hypothesis.!In general, a hypothesis test about the value of apopulation meanμmust take one of the followingthree forms (whereμ0is the hypothesized value ofthe population mean).!Example:Metro EMSNull and Alternative HypothesesOperating in a multiplehospital system withapproximately 20 mobile medicalunits, the service goal is to respond to medicalemergencies with a mean time of 12 minutes or less.A major west coast city providesone of the most comprehensiveemergency medical services inthe world.The director of medical serviceswants to formulate a hypothesistest that could use a sample ofemergency response times todetermine whether or not theservice goal of 12 minutes or lessis being achieved.!Example:Metro EMSNull and Alternative Hypotheses