Bluman A.G. Elementary Statistics- A Step By Step Approach

Section 5–4 Other Types of Distributions (Optional) 29111. Telephone Soliciting A telephone soliciting companyobtains an average of 5 orders per 1000 solicitations. Ifthe company reaches 250 potential customers, find theprobability of obtaining at least 2 orders. 0.355412. Mail Ordering A mail-order company receives anaverage of 5 orders per 500 solicitations. If it sends out100 advertisements, find the probability of receiving atleast 2 orders. 0.264213. Company Mailing Of a company’s mailings 1.5% arereturned because of incorrect or incomplete addresses.In a mailing of 200 pieces, find the probability that nonewill be returned. 0.049814. Emission Inspection Failures If 3% of all cars failthe emissions inspection, find the probability that ina sample of 90 cars, 3 will fail. Use the Poissonapproximation. 0.220515. Phone Inquiries The average number of phoneinquiries per day at the poison control center is 4. Findthe probability it will receive 5 calls on a given day. Usethe Poisson approximation. 0.156316. Defective Calculators In a batch of 2000 calculators,there are, on average, 8 defective ones. If a randomsample of 150 is selected, find the probability of 5defective ones. 0.000417. School Newspaper Staff A school newspaper staff iscomprised of 5 seniors, 4 juniors, 5 sophomores, and7 freshmen. If 4 staff members are chosen at random fora publicity photo, what is the probability that there willbe 1 student from each class? 0.11718. Missing Pages from Books A bookstore ownerexamines 5 books from each lot of 25 to check formissing pages. If he finds at least 2 books with missingpages, the entire lot is returned. If, indeed, there are5 books with missing pages, find the probability that thelot will be returned. 0.25219. Types of CDs A CD case contains 10 jazz albums,4 classical albums, and 2 soundtracks. Choose 3 atrandom to put in a CD changer. What is the probabilityof selecting 2 jazz albums and 1 classical album? 0.32120. Defective Computer Keyboards A shipment of 24computer keyboards is rejected if 4 are checked fordefects and at least 1 is found to be defective. Find theprobability that the shipment will be returned if thereare actually 6 defective keyboards. 0.71221. Defective Electronics A shipment of 24 electrictypewriters is rejected if 3 are checked for defects and atleast 1 is found to be defective. Find the probability thatthe shipment will be returned if there are actually 6typewriters that are defective. 0.597Technology Step by StepTI-83 Plus orTI-84 PlusStep by StepPoisson Random VariablesTo find the probability for a Poisson random variable:Press 2nd [DISTR] then B (ALPHA APPS) for poissonpdf( (Note: On the TI-84 Plus Use C)The form is poissonpdf(l,X).Example: l 0.4, X 3 (Example 5–27 from the text)poissonpdf(.4,3)Example: l 3, X 0, 1, 2, 3 (Example 5–28a from the text)poissonpdf(3,{0,1,2,3})The calculator will display the probabilities in a list. Use the arrow keys to view the entiredisplay.To find the cumulative probability for a Poisson random variable:Press 2nd [DISTR] then C (ALPHA PRGM) for poissoncdf( (Note: On the TI-84 Plus Use D)The form is poissoncdf(l,X). This will calculate the cumulative probability for values from 0 to X.Example: l 3, X 0, 1, 2, 3 (Example 5–28a from the text)poissoncdf(3,3)5–41