Exam 9: Hypothesis Testing: Single Population

A music industry professional claims that the average amount of money that an average teenager spends per month on music is at least $50.Based upon previous research,the population standard deviation is estimated to be $12.42.The music professional surveys 20 students and finds that the mean spending is $47.77.Is there evidence that the average amount spent by students is less than $50?

The Next Questions Are Based On The Following Information: The dean of a business college in the Midwest claims that he can correctly identify whether a student is a finance major or a music industry management major by the way the student dresses.Suppose in actuality that he can correctly identify finance majors 84% of the time,while 16% of the time he mistakenly identifies a music industry management major as a finance major.Presented with one student and asked to identify the major of this student (who is either a finance or music industry management major),the dean considers this to be a hypothesis test with the null hypothesis being that the student is a finance major and the alternative that the student is a music industry management major. -Which of the following statements illustrates a Type I error?

The Next Questions Are Based On The Following Information: Research and development has designed a ball point pen so that the true average writing lifetime under controlled conditions (involving the use of a writing machine)is at least 12 hours.A random sample of 18 pens is selected,the writing lifetime of each is determined,and a normal probability plot of the resulting data supports the use of a one-sample t test. -What conclusion is appropriate for the hypotheses H₀ : μ = 12 against H₁ : μ < 12,,and the test statistic t = -2.5,and α = .05?

Suppose that you want to test H₀ : μ = 277 against H₁ : μ ≠ 277 at α = 0.10,and you know that the population standard deviation σ = 13.5.If you randomly select a sample of 20 observations,for what values of the sample mean will you reject the null hypothesis?