A shareholders' group is lodging a protest against your company. The shareholders group claimed that the mean tenure for a chief exective office (CEO) was less than 8 years. A survey of 88 companies reported in The Wall Street Journal found a sample mean tenure of 5.4 years for CEOS with a standard deviation of 5.9 years (The Wall Street Journal, January 2, 2007). 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 significance level of 0.05. Your hypotheses are: Ho: µ > 8 H1: µ < 8 What is the test statistic for this sample? (Report answer accurate to 3 decimal places.) What is the p-value for this sample? (Report answer accurate to 4 decimal places.) This test statistic leads to a decision to reject the null Uaccept the null fail to reject the null As such, the final conclusion is that there is sufficient evidence to conclude that the population mean tenure for CEOS is equal to 8. there is not sufficient evidence to conclude that the population mean tenure for CEOS is equal to 8. O there is sufficient evidence to conclude that the population mean tenure for CEOS is less than 8. there is not sufficient evidence to conclude that the population mean tenure for CEOS is less than 8.

Fran is training for her first marathon, and she wants to know if there is a significant difference between the mean number of miles run each week by group runners and individual runners who are training for marathons. She interviews 42 randomly selected people who train in groups and finds that they run a mean of 47.1 miles per week. Assume that the population standard deviation for group runners is known to be 4.4 miles per week. She also interviews a random sample of 47 people who train on their own and finds that they run a mean of 48.5 miles per week. Assume that the population standard deviation for people who run by themselves is 1.8 miles per week. Test the claim at the 0.01 level of significance. Let group runners training for marathons be Population 1 and let individual runners training for marathons be Population 2.   Step 2 of 3 :   Compute the value of the test statistic. Round your answer to two decimal places.

Many people consider their smart phone to be essential! Communication, news, Internet, entertainment, photos, and just keeping current are all conveniently possible with a smart phone. However, the battery better be charged or the phone is useless. Battery life of course depends on the frequency, duration, and type of use. One study involving heavy use of the phones showed the mean of the battery life to be 11.25 hours with a standard deviation of 3.3 hours. Then the battery needs to be recharged. Assume the battery life between charges is normally distributed. (a) Find the probability that with heavy use, the battery life exceeds 12 hours. (Round your answer to four decimal places.)(b) You are planning your recharging schedule so that the probability your phone will die is no more than 5%. After how many hours should you plan to recharge your phone? (Round your answer to the nearest tenth of an hour.) hours

You may need to use the appropriate technology to answer this question. 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 x7.27 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. H29 (b) Assume 90 companies were included in the sample. What is the test statistic? (Round your answer to three decimal places.) 1356 x What is the p-value for your hypothesis test? (Round your answer to four decimal places.) p-value - 242 x (c) At a- 0.01, what is your conclusion? O Reject H 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 Hg. We cannot conclude that the mean tenure of a CEO is significantly lower than 9…