Practice Question #1: A gambler claims he can predict the roll of a die more often than chance would predict. To test this‚ a die is rolled 100 times and the gambler guesses the number that comes up twenty times and guesses incorrectly the other eighty times. Is this strong evidence that the gambler’s claim is true? a. Specify the null and alternative hypothesis for this problem. p = probability gambler guess correctly for an individual roll null (Ho): p = 1/6 alternative (Ha): p > 1/6 b
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Reject? We accept a null hypothesis when the significance level greater than .05 Reject when less than .05 Confidence Intervals First you have to know three things: Statistical inference: the process of using sample statistics to estimate population parameters. Confidence level: the probability that a population parameter lies within a given confidence interval Confidence interval: the range of values in which the population parameter is estimated to fall. A statistic is an estimate of
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identify topics that would be of interest to readers. Your report should address the follow- ing issues‚ but do not limit your analysis to just these areas. a. Develop appropriate descriptive statistics to summarize the data. b. Develop 95% confidence intervals for the mean age and
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done to 30 bottles to figure out if what the customers are saying is true about the sodas that are being produced is less than what is advertised. Of the 30 bottles the mean‚ median‚ and standard deviation for the ounces in the bottles. A 95% confidence interval will be calculated as well. A hypothesis test will be done to verify if the claim is true and also a conclusion will be made. To see if what the customers are saying is true about the ounces in the bottles are actually less than
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(1) What percentage of the population are we willing to exclude? (2) How much extra room do we want to provide for passenger comfort and safety? Use the available information to determine the sitting distance. Identify the choices and decisions that were made in that determination. Mean Standard Deviation Distribution Males 23.5 in. 1.1 in. Normal Females 22.7 in. 1.0 in. Normal Part I- Answer: In order for an airline company to be profitable‚ it has to differentiate itself from others
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s is a good point estimate for σ.) Otherwise‚ we need to use a different shape of probability distribution function that will consider an error on σ. Lecture 12 - CHEE 231 – Fall 2013 – Prof. Girard-Lauriault 3 Confidence Interval on the mean‚ small sample (n≤30) & Variance unknown Let X1‚ X2‚ … ‚Xn be a random sample from a normal distribution with unknown mean and variance. The random variable: X −µ T= S
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Case Problem 1: National Health Care Association(Descriptive Statistics) The National Health Care Association is concerned about the shortage of nurses the health care profession is projecting for the future. To learn the current degree of job satisfaction among nurses‚ the association has sponsored a study of hospital nurses throughout the country. As part of this study‚ a sample of 50 nurses was asked to indicate their degree of satisfaction in their work‚ their pay and their opportunities for
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means that new balls have greater variability of driving distances. 4. =0.05 t0.025=2.0227 d.f=39 The confidence interval of current balls is [267.475‚ 273.0775] The confidence interval of current balls is [264.33‚ 270.67] Interval estimation of the difference between the means of two populations =76.85 We take 77 as degree of freedom‚ t0.025=1.991 Confidence interval [-1.385‚ 6.935] 5. The management of Par Inc.‚ wants to use the new golf balls to increase market share but
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I read Barron’s How to Prepare for the AP Statistics Exam. A very educational book helped a lot on the AP test. It clarified ideas that I was uncertain on. It helped me to understand when to use each test and the assumptions needed for each test. Type I and Type II errors were explained in such a way that they became crystal clear to me instead of muddy. Computer and Minitab outputs were thoroughly explained‚ and I became comfortable with them after reading this book. The Barron’s guide also
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Bock Investment Services Lisa started Bock Investment services in 1994 with the goal of making BIS the leading money market advisory service in Southern Carolina. To provide better service for her present clients and to attract new clients‚ she has developed a weekly newsletter. Lisa has been considering adding a new feature to the newsletter that will report the result of a weekly telephone survey of fund managers. To investigate the feasibility of offering this service and to determine what type
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