please answer 12

12. DETAILS MENDSTAT15M 10.2.019. MY NOTES ASK YOU The following n = 10 observations are a sample from a normal population. 7.4 7.0 6.4 7.5 7.6 6.3 6.8 7.6 6.4 6.9 (a) Find the mean and standard deviation of these data. (Round your standard deviation to four decimal places.) mean standard deviation (b) Find a 99% upper one-sided confidence bound for the population mean u. (Round your answer to three decimal places.) (c) Test Ho: u = 7.5 versus Ha: u t<