Level Of Significance

Question

1) If you use a 0.01   level of significance in a (two-tail) hypothesis test, what is you decision   rule for rejecting a null hypothesis that the population mean is 500 if you   use the Z test?      

2) Do students at your school study more,   less or about the same as at other business schools? Business Week reported   that at the top 50 business schools, students studied an average of 14.6   hours (data extracted from “Cracking the Books” SPECIAL   REPORT/online extra). Set up a   hypothesis test to try to prove that the mean number of hours studied at your   school is different from the 14.6 hour benchmark reported by Business Week.   

a) State the null and alternative   hypotheses.  

 b) What is a Type 1 error for your test?   

c) What is a Type 2 error for your test?     

 3) the quality control manager at a   lightbulb factory needs to determine whether the mean life of a large   shipment of lightbulbs is equal to the specified value of 375 hours. State   the null and alternative hypotheses.  

Question

A  report by the NCAA states that 57.6% of football injuries occur during practices. A head trainer claims that this is too high for his conference, so  he randomly selects 42 injuries and finds that 20 occurred during practices.  Follow the steps below to conduct a hypothesis test to determine, at the 5%  significance level, if the percentage of football injuries received in  practices for the head trainer’s conference is less than 57.6%.    

  (a) List the null and alternative hypotheses   for this test.   

 (b) Determine the value of the sample’s test statistic.   

 (c) Determine the critical value(s).    

(d) Determine the P-value.    

(e) Write a final interpretive sentence tied to the context for the   hypothesis test results.