Statistics: Testing a claim About a mean of voltage from UPS
According to a Data Set, the list measures voltage amounts obtained from the author’s back-up UPS (APC model CS 350). According to the manufacturer, the normal output voltage is 120 volts. The 40 measured voltage amounts from the data set have a mean of 123.59 volts and a standard deviation of 0.31 volt. Use a 0.05 significance level to test the claim that the sample is from a population with a mean equal to 120 volts.
(i) H0: µ =
(ii) H1: µ =
(iii) Critical values: t =
(iv) Test statistic [Show procedure.] t =
(vi) Final conclusion (in the words of the problem):