Microsoft excel was used on a set of data involving the number of defective items found in a random sample of 46 cases of light bulbs produced during a morning shift at a plant. A manager wants to know if the mean number of defective bulbs per case is greater than 20 during the morning shift. She will make her decision using a test with a level of significance of 0.10. The following information was extracted from the microsoft excel output for the sample of 46 cases: n=46, Arithmetic mean=28.00, Std Dev =25.92, standard error=3.82, Null hypothesis: H0 : u<=20, alpha =0.10, df=45, t-test statistic=2.09, one tail test upper critical value =1.3006, p-value=0.021
i) what parameter is the manager interested in?
ii) state the alternative hypothesis for this study.
iii) what critical value should the manager use to determine the rejection region.
iv) explain if the, null hypothesis should be rejected and why or why not?
v) explain our risk of committing of a type1 error.
vi) explain if the data evidence proves beyond a doubt that the mean number of defective bulbs per case is greater than 20 during the morning shift
vii) what can the manager conclude about the mean number of defective bulbs per case during the morning shift using a level of significance of 0.10?
viii) what would the p-value be if these data were used to perform a two tail test?