PART A

HOW good of a witness are you? Often, a witness to a crime will look at a lineup of potential criminals to iclentil'g.r the person he or she saw commit the crime. Witness Says Guilty Witness Says Innocent Person Is Guilty:r Person Is Innocent Calculate they: test statistic. (Round youranswerto two decimal places.) :| Are mechanical engineers more likely to be left-handed than other types of engineers? Here are some data on handedness of a sample of engineers. Left Right Total Mechanical 13 101 114 Other 28 250 278 Total 41 351 392 Calculate the x- test statistic. (Round your answer to two decimal places.)New TV shows air each fall. Priorto getting a spot on the air, tests are run to see what public opinion is regarding the show. Here are data on a new show. Is there an association between liking the show and the age of the viewer? 1a) What is the probability that a person selected at random from this group is an adult who likes the show? {Enter your probability as a fraction] |:| r {in} What is the probability that a person selected at random who likes the show is an adult? (Enter your probability as a fraction.) |:| {c} What is the expected value for the adults who dislike the show? {Round your answer to two decimal places.) |:| {de Calculate they: test statistic. (Round your answer to two decimal places.) |:| In order to sell items, you need potential consumers to look at your product. One place that people can look is on your website. In a marketing study, data were collected on the length of time people spent on a website compared to whether a purchase was made. No Purchase Purchase Total 0-10 Minutes 1,000 500 1,500 10-20 Minutes 2,500 2,500 5,000 20+ Minutes 500 3,000 3,500 Total 4,000 6,000 10,000 (a) What is the probability that a person selected at random spent less than 10 minutes and made a purchase? (Enter your probability as a fraction.) (b) What is the probability that a person selected at random who spent 20+ minutes on the website made a purchase? (Enter your probability as a fraction.) (c) What is the expected value for the purchases made when 0-10 minutes were spent on the website? (c) Calculate the y test statistic. (Round your answer to two decimal places.)