The output voltage of a power supply is assumed to be normally distributed Ten observations taken at random on voltage are as follows:
11.25, 9.58, 11.54, 9.95, 10.28, 8.37, 10.44, 9.25, 9.38, and 10.85.
a. Compute the mean, range, and standard deviation of the data set
b. Test the hypothesis that the mean voltage equals 12 V against a two-sided alternative using alpha = 0.05.
c. Construct a 95% two-sided confidence interval on mu. What is your conclusion based on the confidence interval?