1. Classify the hypothesis test as two-tailed, left-tailed, or right-tailed. In
ID: 3318494 • Letter: 1
Question
1. Classify the hypothesis test as two-tailed, left-tailed, or right-tailed. In the past, the mean running time for a certain type of flashlight battery has been k days. The manufacturer has introduced a change in the production method and wants to perform a hypothesis test to determine whether the mean running time has changed as a result.
2. A hypothesis test is to be performed for a population proportion. For the given sample data and null hypothesis, compute the value of the test statistic, z = A drug company claims that over 90% of all physicians recommend their drug. 800 physicians were asked if they recommend the drug to their patients. 39% said yes. H0: p = 0.9
3. Perform a hypothesis test for the population mean. Assume that preliminary data analyses indicate that it is reasonable to apply the z-test. A national car insurance company stated that in 1987, the average yearly car insurance cost for a family in the U.S. was $1,716. In the same year, a random sample of 34 families in California resulted in a mean cost of $ 2011. Does this suggest that the average insurance cost for a family in California in 1987 exceeded the national average? Perform the hypothesis test at a significance level of 10%. Assume that the population standard deviation is $35.50.
Explanation / Answer
Ans:
1)two tailed
2)std dev.=sqrt(0.9*(1-0.9)/800)=0.0106
z=(0.39-0.90)/0.0106=-48.11
3)
z=(2011-1716)*sqrt(34)/35.5=48.45
p-value=P(z>48.45)=0
As,p-value>0.1,we reject null hypothesis.
We have sufficient evidence to suggest that the average insurance cost for a family in California in 1987 exceeded the national average
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.