A shareholders' group in lodging a protest, claimed that the mean tenure for a chief executive office (CEO) was at least nine years. A survey of companies reported in The Wall Street Journal found a sample mean tenure of x = 7.27 years for CEOs with a standard deviation of s = 6.38 years. (a) Formulate hypotheses that can be used to challenge the validity of the claim made by the shareholders' group. 9 o Ho> 9 HUS9 (b) Assume 95 companies were included in the sample. What is the test statistic? (Round your answer to three decimal places.) What is the p-value for your hypothesis test? (Round your answer to four decimal places.) D-value = (c) At a = 0.01, what is your conclusion? Reject Ho. We can conclude that the mean tenure of a CEO is significantly lower than 9 years. The claim of the shareholders group is not valid. Reject Ho. We cannot conclude that the mean tenure of a CEO is significantly lower than 9 years. The claim of the shareholders group is valid Do not reject Ho. We can conclude that the mean tenure of a CEO is significantly lower than 9 years. The claim of the shareholders group is not valid. O Do not reject Ho. We cannot conclude that the mean tenure of a CEO is significantly lower than 9 years. The claim of the shareholders group is valid