1. Calculate the expected value, the variance, and the standard deviation of the given random variableX. (Round all answers to two decimal places.)Xis the number of red marbles that Suzan has in her hand after she selectsthreemarbles from a bag containingthreered marbles and two green ones.

2. In your bid to be elected class representative, you have your election committee survey five randomly chosen students in your class and ask them to rank you on a scale of 0-10. Your rankings are9,6,8,7,0.(a) Find the sample mean and standard deviation. (Round your answers to two decimal places.) HINT [See Example 1.]

sample mean
standard deviation

(b) Assuming the sample mean and standard deviation are indicative of the class as a whole, in what range does the empirical rule predict that approximately 68% of the class will rank you?