It is necessary for an automobile producer to estimate the number of miles per g

Question

It is necessary for an automobile producer to estimate the number of miles per gallon achieved by its cars. Suppose that the sample mean for a random sample of 120 cars is 30.6 miles and assume the standard deviation is 2.1 miles. Now suppose the car producer wants to test the hypothesis that mu, the mean number of miles per gallon, is 28.6 against the alternative hypothesis that it is not 28.6. Conduct a test using alpha =.05 by giving the following: (a) positive critical z score (b) negative critical z score (c) test statistic The final conclustion is A. There is not sufficient evidence to reject the null hypothesis that mu = 28.6. B. We can reject the null hypothesis that mu = 28.6 and accept that mu notequalto 28.6.

Explanation / Answer

a) here poistive critical value =1.96

b)negative critical value=-1.96

c)std error of mean =std deviation/(n)1/2 =0.1917

test statistic=(X-mean)/std error =(30.6-28.6)/0.1917=10.4328

option B is correct

Related Questions

Navigate

• Browse (All)
• Browse I
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.