Statistics Help
Question: The sample mean is found to be 0.498 in. Assume that the standard deviation of all such lengths is 0.12 in, and use a 0.05 significance level to test the chain that the screws have a mean length equal to 1/2in [or 0.5 in], as indicated on the package labels. Do the screw length appear to be consistent with the package label?
H0:μ =0.05
H1:μ ≠0.05
What is the test statistic? Edit
Answer: H0: μ =0.5
H1:μ ≠0.5
test statistic, z= (x bar - mu)/sigma= (x bar - 0.498)/0.12
x bar=0.5
z= (0.5-0.498)/0.12=0.016
z-critical at 0.05 level of significance= 1.96
hence, z computed < z-critical
so, fail to reject null .
so, the screw length appear to be consistent with the package label. Edit
TutorTeddy.com & Boston Predictive Analytics
[ Email your Statistics or Math problems to help@teddycan.com (camera phone photos are OK) ]
Boston Office (Near MIT/Kendall 'T'):
Cambridge Innovation Center,
One Broadway, 14th Floor,
Cambridge, MA 02142,
Phone: 617-395-8864
Dallas Office (Near Galleria):
15950 Dallas Parkway,
Suite 400,
Dallas, TX 75248,
Phone: 866-930-6363