One of the items on a student survey for an introductory sta…

One of the items on a student survey for an introductory statistics course was “Rate your intelligence on a scale of 1 to 5.” Here is the distribution of this variable for the students in the class. Intelligence Rating (X) Proportion or p(X) 1 0 2 .1 3 .2 4 .3 5 .4   A.) What is the average intelligence rating for the students? (In other words, what is the expected value, E(X)?) [a]   B.) What is the standard deviation, SD(X)? [b] Retype your answer [c]   Note: If needed, type your answer to three decimal places.

A Quinnipiac University poll conducted from Jan 28 to Feb 1,…

A Quinnipiac University poll conducted from Jan 28 to Feb 1, 2021 asked 1075 Americans, “Do you think that the coronavirus pandemic in the United States is a crisis, a problem but not a crisis, or not a problem at all?” 68% said “a crisis”. (Use at least 3 decimal places once the 0’s stop in your computations for this problem, but still enter your final answers to 3 decimals.) If you were to find a 95% confidence interval for the proportion of all Americans who thought it was a crisis, would you use a z-value (Z) or a t-value (T)? [a] What would its numerical value be? [b]   Find a 90% confidence interval for the proportion of all Americans who would also say “a crisis”. [c] [d] or ( [e] , [f] )

    Suppose a 3-step experiment is comprised of Event 1 fol…

    Suppose a 3-step experiment is comprised of Event 1 followed by Event 2 followed by Event 2 again. The outcomes for each step are independent of each other. Use the information in the graphical displays to determine the various probabilities. (Hint: You may want to start by filling out the tree diagram) (Additional Hint for non-native English speakers: The letters A, E, I, O, or U are considered vowels.)   What is the probability of obtaining exactly two vowels?