Intro To Statistics, I need Help


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I have gone over and over and over the material in the book for the past 2 weeks but its like im reading doesnt make sense at all, it doesnt even look homework is due tomorrow at 7am and I cant figure out anything beyond the frst question, I have been sitting here for 5 hours immobilized trying to figure out questions 2 and 3, im very frustrated and dont want an F Document Preview: MAT 120 Name: Test 2 (v1) Please be neat. Sloppiness, disorganization, etc. may, in the aggregate, result in a point reduction. Please show all work. No credit for correct final answer without a valid argument. Show your work graphically in all relevant questions. Use the formula, substitution, answer method whenever possible. 1. The amazing car dealer in Greater Portland area has complied the sales data for the past five years and developed the following probability distribution: x 10 11 12 13 14 15 p(x) 0.30 .25 0.10 .15 .15 .05 where X is the number of cars sold per day. (i) (2 pts.) What is the probability that at least 12 cars are sold in a given day? (ii) (2 pts.) What is the expected value of X (i.e. the mean sales per day). (iii) 2 pts.) What is the standard deviation of X. 2. (2 pts.) Statistics indicate that alcohol is a factor in about 60% of fatal automobile accidents. Of the next 6 accidents, find the probability that alcohol is a factor in at least 5, that is p(X 5). Use the binomial formula. 3. (2 pts.) Suppose that each item produced is independently defective with probability 0.001. Find the mean and standard deviation of the number of defective items produced in a shipment of size 5000. (No formula, no credit). 4. (2 pts.) Suppose that patients arrive at an emergency room at a mean rate of 5 patients per hour. Using the Poisson model find the probability that 3 patients arrive during one hour. 5. (2 pts.) Let Z be a standard normal distribution. Find z0 such that p(Z z0) = 0.07, that is z.07. (Show your work graphically). 6. The height of adult women in the United States, X, is normally distributed with mean 64.5 inches and standard deviation 2.4 inches. (i) (2 pts.) Alice is 72 inches tall. What percentage of women are taller than Alice. 7. The time, X, in hours required by a mechanic to repair a machine has an exponential distribution with = 0.5. (i) (2 pts.) What is the probability that the time until the machine is repaired exceeds 2.5 hours?... Attachments: t2v1-120.pdf Mar 21 2014 04:44 AM


Solution ID:608793 | This paper was updated on 26-Nov-2015

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