its is known that 90 % of all personal computer of a particular model will operate for at least 1 year before needing repair . a manager purchase two of these computers a. find the probablity that both computers will work for at least 1 year before needing repair b. find the probablity that at least 1 computer will work

its is known that 90 % of all personal computer of a particular model will operate for at least 1 year before needing repair . a manager purchase two of these computers a. find the probablity that both computers will work for at least 1 year before needing repair b. find the probablity that at least 1 computer will work

A First Course in Probability (10th Edition)

10th Edition

ISBN:9780134753119

Author:Sheldon Ross

Publisher:Sheldon Ross

Chapter1: Combinatorial Analysis

Section: Chapter Questions

Problem 1.1P: a. How many different 7-place license plates are possible if the first 2 places are for letters and...

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Many investors and financial analysts believe the Dow Jones Industrial Average (DJIA) gives a good barometer of the overall stock market. On January 31, 2006, 9 of the 30 stocks making up the DJIA increased in price (The Wall Street Journal, February 1, 2006). On the basis of this fact, a financial analyst claims we can assume that 30% of the stocks traded on the New York Stock Exchange (NYSE) went up the same day.A sample of 60 stocks traded on the NYSE that day showed that 24 went up.You are conducting a study to see if the proportion of stocks that went up is significantly more than 0.3. You use a significance level of α=0.001α=0.001.What is the test statistic for this sample? (Report answer accurate to three decimal places.)test statistic = What is the p-value for this sample? (Report answer accurate to four decimal places.)p-value =
A salon owner estimates the number of clients she is expecting during the festive season to be 20% during Monday to Wednesday, 20% on Thursday and 60% over the weekend. She therefore hires additional staff to assist during the weekend to meet the client demand. She however only observes 30% during Monday to Wednesday, 20% on Thursday and 50% over the weekend in the first week of December. The salon owner is uncertain whether she should reduce the planned staff for the December festive period due the observed trend or not. She conducts a statistical test at α = 0.05 to determine if the observed trend fits the expected trend. Which of the following statements is true? A. The conclusion of the test is that she should not keep the additional staff for the weekend. B. The df for this test is 3. C. The p-value is greater than α. D. The null hypothesis is that the observed trend is different to the expected trend. E. The test statistic is χ2 = 5.33.
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Suppose you are a production manager for a small firm that manufactures designer phone cases. Your production facility utilizes three machines. Quality is binary — each phone case is either defective or it is not defective. Each hour, Machines 1, 2, and 3 produce 10, 10 and 20 phone cases, respectively. But because the machines differ slightly in their technology, data on past production has shown that they differ in terms of their rates of defective output — specifically, Machines 1, 2, and 3 have rates of defective production of 2%, 4%, and 5%, respectively. If one phone case is selected randomly from one hour’s total output, and that phone case is found to be defective, what is the probability that it was produced by Machine 1? Machine 2? Machine 3?
It is known that in any given year, • 90% of the people in a city move to the suburbs; • 80% of the people in the suburbs do not move to the city. Given an initial city population of 55,000 and an initial suburb population of 77,000, what are the long-term population levels of the city and the suburb?
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Many investors and financial analysts believe the Dow Jones Industrial Average (DJIA) gives a good barometer of the overall stock market. On January 31, 2017, 9 of the 30 stocks making up the DJIA increased in price. On the basis of this fact, a financial analyst claims we can assume that 55% of the stocks traded on the New York Stock Exchange (NYSE) went up the same day. A sample of 79 stocks traded on the NYSE that day showed that 48 went up. You are conducting a study to see if the proportion of stocks that went up is significantly different from 55%. You use a significance level of a = 0.025. 1. For this study, we should use Select an answer 2. The null and alternative hypotheses would be: Ho:? v Select an answer v (please enter a decimal) Hi:? vSelect an answer v (Please enter a decimal) 3. The test statistic (please show your answer to 3 decimal places.) 4. The p-value = (Please show your answer to 4 decimal places.) 5. The p-value is ? va 6. Based on this, we should Select an…
Many investors and financial analysts believe the Dow Jones Industrial Average (DJIA) gives a good barometer of the overall stock market. On January 31, 2017, 9 of the 30 stocks making up the DJIA increased in price.On the basis of this fact, a financial analyst claims we can assume that 54% of the stocks traded on the New York Stock Exchange (NYSE) went up the same day. A sample of 74 stocks traded on the NYSE that day showed that 35 went up. You are conducting a study to see if the proportion of stocks that went up is significantly smaller than 54%. You use a significance level of α=0.05α=0.05. how to you come up with the test statistic and p value using excel
A gerontologist investigating various aspects of aging process wanted to see whether staying “ lean and mean, “ that is, being under normal body inbred line to one of three diets: (1) unlimited access to food, (2) 90% of the amount of food that a rat of size would normally eat, or (3) 80% of amount of food that a rat of the size would normally eat. She maintained the rats on three diets throughout their lives and recorded their lifespans (in years). Five rates in each group. Is there evidence that diet affected life span in this study? Let α= 0.01 Complete the ANOVA table . Source of variation df SS MS Fc Treatment 2 1.575 Error 12 Total 14 5.60 A) Hypothesis Test H0: H1: B) Test Statistic C) Decision Rule d) Conclusion *(please with equations and explanation) and thamnk you