A shareholders' group is lodging a protest against your company. The shareholders group claimed that the mean tenure for a chief exective ofce (CEO) was at least 11 years. A survey of 78 companies reported in The Wall StreetJournal found a sample mean tenure of 9.5 years for CEOs with a standard deviation of 's=' 5 years (The Wall StreetJournal, January 2, 2007). You don't know the population standard deviation but can assume it is normally distributed. You want to formulate and test a hypothesis that can be used to challenge the validity of the claim made by the group, at a signicance level of 'alpha = 0005'. Your hypotheses are: 'H_o:mu >=1'l' 'H_a '. mu