get a standard deviation of 0.55 (rounded down to two decimal places). Construct a 95% Confidence Interval for the ounces in the bottles. In order to construct a confidence interval, we need several statistics. The first is the sample mean, which is 14.9. Since we have selected a confidence interval of 95%, we need to find the margin of error to calculate our findings. Using the t-score model ( compute alpha, find the critical probability [.975], the degrees of freedom [999]) (StatTrek, 2013)
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TI-84 Plus TI-84 Plus Silver Edition Guidebook Important Information Texas Instruments makes no warranty, either express or implied, including but not limited to any implied warranties of merchantability and fitness for a particular purpose, regarding any programs or book materials and makes such materials available solely on an "as-is" basis. In no event shall Texas Instruments be liable to anyone for special, collateral, incidental, or consequential damages in connection with or arising out
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have significantly different means. This can be tested by calculating the confidence intervals of the means of the three subgroups (probability 95%) by means of Y ̅±t*s_Y ̅ . If two confidence intervals don’t have any common point, then their population means differ significantly. Otherwise there is no significant difference. I compute these confidence intervals and by plotting them it is obvious that the confidence interval for
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population mean for the confidence interval with a lower bound of 25 and an upper bound of 35. 3) _____ A) 35 B) 25 C) 30 D) 31 4) Compute the critical value z* that corresponds to a 94% level of confidence. 4) _____ A) 1.96 B) 1.645 C) 2.33 D) 1.88 5) In a sample of 10 randomly selected employees, it was found that their mean height was 63.4 inches. From previous studies, it is assumed that the standard deviation, σ, is 2.4. Compute the 95% confidence interval for μ. 5) _____ A) (59
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TAILED | LOWER TAIL | UPPER TAIL | z calc ≤ -z crit OR z calc ≥ +z crit | z calc ≤ -z crit | z calc ≥ +z crit | Proportions are worked the same way except that they always use z z = | HO TRUE | HO FALSE | ACCEPT HO | Probability = 1-α (confidence)This is correct | Probability = βType II errorConsumer (β) risk | REJECT HO | Probability = αType I errorProducer (α) risk | Probability = 1-β (power of test)This is correct | CHAPTER 10 TWO TAILED | LOWER TAIL | UPPER TAIL | Ho : µ1
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20 HA : µ < 20 A sample of 40 provided a sample mean of 19.4. The population standard deviation is 2. (a) Create a 95% confidence interval for the mean. We know σ, therefore we should use the z − table. This is a one-tailed (lower tail) test, so the 95% confidence interval will be given then by σ x − z.05 √ , ∞ ¯ n 2 19.4 − 1.65 √ , ∞ 40 The 95% confidence interval is µ ∈ [18.878, ∞). (b) What is the p-value? The p-value is the area in the lower tail. First, we calculate the z-value:
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started to compute the chi-square statistic, the degrees of freedom is 4-3=1. Now the theory says that you must use the chi-quare table with one degree of freedom. Confidence Level A confidence level refers to the likelihood that the true population parameter lies within the range specified by the confidence interval . The confidence level is usually expressed as a percentage. Thus, a 95% confidence level implies that the probability that the true population parameter lies within the confidence interval
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Bootstrapping (statistics) From Wikipedia, the free encyclopedia In statistics, bootstrapping is a method for assigning measures of accuracy (defined in terms of bias, variance, confidence intervals, prediction error or some other such measure) to sample estimates.[1][2] This technique allows estimation of the sampling distribution of almost any statistic using only very simple methods.[3][4] Generally, it falls in the broader class of resampling methods. Bootstrapping is the practice of estimating
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estimate of π. Underlying Sample distribution is binomial and can be approximated by normal if: nπ ≥ 5 and n(1- π) ≥ 5. With resulting mean equal to μp=π and standard error equal to σp=π(1-π)n Therefore: WEEK 8 CONFIDENCE INTERVALS: CONFIDENCE INTERVAL FOR μ (σ Known): Assume standard deviation is known, population is normally distributed. If not
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Case Problem Set 3: Problem 1: Young Professional magazine was developed for a target audience of recent college graduates who are in their first 10 years in a business/professional career. In its two years of publication the magazine has been fairly successful. Now the publisher is interested in expanding the magazine’s advertising base. Potential advertisers continually ask about the demographics and interests of subscribers to Young Professional. To collect this information the magazine has
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