Quiz 11: Part IV Hypothesis testing • Name:
Gnihton
stegdiw length /retems 
4.7 
4.8 
4.9 
5.0 
5.1 
On the planet Tau Centauri IV2 the Gnihton corporation produces stegdiws. A stegdiw should be 5 retems long. Allegations arose from customers that Ghihton was producing stegdiws that were too short. An inspector from the Coordinating Council for Clarity in Commerce and Competition (C^{5}) collected a random sample n of five stegdiws. The measure of each of the five stegdiws collected is given in the table. Run a hypothesis test to determine whether the five stegdiws could or could not have come from a population of stegdiws with a population mean µ length of 5 retems at a 5% level of significance. Use a population mean µ of 5 retems.
 _________ What level of measurement is the data?
 _________ Determine the sample size n.
 _________ Calculate the sample mean
x.
 _________ Determine the median.
 _________ Determine the mode.
 _________ Determine the minimum.
 _________ Determine the maximum.
 _________ Calculate the range.
 _________ Calculate the sample standard deviation sx.
 _________ Calculate the sample Coefficient of Variation.
 ________________________________________ Write the null hypothesis in formal statistical format.
 ________________________________________ Write the alternate hypothesis in formal statistical format.
α = 0.05.
 t_{c} = __________ Determine t_{critical}.
 t = __________ Calculate the tstatistic.
 p = __________ Determine the pvalue using the tdistribution.
 __________ What is the largest confidence interval c for which this difference is statistically significant?
 ________________________________________ Would we reject the null hypothesis or fail to reject the null hypothesis that the sample mean is statistically significantly different from the population mean at a 5% level of significance?
 __________ If we reject the null hypothesis, what is the risk of a type I error based on the pvalue?
 __________ Can the C^{5} prove that the Gnihton corporation is producing stegdiws that are too short at a 5% level of confidence?
Hypothesis Testing 
Calculate tcritical for a twotailed test 
t_{c}   =TINV(α;df) 
Calculate a tstatistic 
t 

=(x  µ)/(sx/SQRT(n)) 
Calculate a twotailed pvalue from a tstatistic  p  
= TDIST(ABS(t);df;2) 