Submit completed tests as word or pdf files via email to paul.kurose@seattlecolleges.edu Due: Sunday, May 19 (by 8am). 1. a) In Chapter 6, you learned to find interval estimates for two population parameters, a population mean and a population proportion. Explain the meaning of an interval estimate of a population parameter. An interval estimate for a specified population parameter (such as a mean or proportion) is a range of values in which the parameter is estimated to lie. In Chapter 6, you were assigned to find interval estimates for a population mean and a population proportion. b) Is finding an interval estimate an example of inferential or descriptive statistics? Explain. It is an interval estimate is an example of The sample size needed is 2401 5. Go to the Gallup Poll website: http://www.gallup.com/poll/158060/unadjusted-unemployment-mid-october.aspx to find an estimate of U.S. Unemployment Rate. a) Identify the population parameter for which the estimate is given. The unemployment rate of the U.S. is 7.3% b) Identify the point estimate, margin of error, and confidence level for the given estimate. The point estimate is 7.64 and the margin of error is 0.26 and the level of confidence given is 95% c) Identify the sample size used and briefly describes how the survey was conducted. The sample size was more than 30.000 U.S. Adult and the survey was conducted by randomly calling the participants on their cellphone or house lines. d) Identify two sources of potential error or bias (identified in the article) in addition to sampling error. The randomness of their sample, a case could be made that they may have missed more unemployed because they lost their phones due to their unemployment thus cannot participate. It was also bease on those that answered the phones, which can potentially skew the results in that maybe those that didn’t answer were employed and busy at work giving the unemployed more chances of answering their calls. 6. Write the null and alternative hypothesis corresponding to the given claim. Identify the test as left-tailed, right-tailed, or two-tailed. a) A
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Means = Chi Square Hypothesis Test(8) Confidence Interval one of 3 tools of statistical inference统计推断 A range of values ( an interval) from a random sample used to estimate the true unknown population parameter ( Think of a “fisherman’s net” Example: “52% is an example of a confidence interval for the population of those that will vote for me Confidence Level of a Confidence Interval The “success rate” of the confidence interval calculation process Overlaps the true parameter of interest…
a type II error) Alternative hypothesis: The hypothesis that the researcher wants to prove or verify; a statement about the value of a parameter that is either “less than,” “greater than,” or “not equal to.” ANOVA (Analysis of Variance): a statistical procedure for testing the equality of multiple means using variances. Central Limit Theorem: The name of the statement telling us that when sampling from a non-Normal population, the sampling distribution of ¯ is approximately Normal whenever…
Zhaoxia Xu Agenda Linear regressions Simple linear model Ordinary Least Squares Estimations Inferences Applications 1 Financial Econometrics Application of statistical techniques to problems in finance Estimating and testing relationships between variables as suggested by theories in finance, e.g. CAPM or APT Modeling and forecasting asset returns Evaluating the performance of portfolio management Examining determinants of firms’ financial decisions…
within one standard deviation of the mean. Similarly, 95.45% of the values lie within two standard deviations of the mean. Nearly all (99.73%) of the values lie within three standard deviations of the mean. 7-11-13 Rule Acceptance sampling a statistical procedure for accepting or rejecting a batch of merchandise or documents; involves determining the maximum number of defects discovered in a sample before the entire batch is rejected 验收抽样 Addition rule for disjoint events If A and B are disjoint…
The conditional probability distribution of X, given Y = y, is P ( x | y) = P ( X = x,Y = y) P (Y = y) The height of a normal density curve at any point x is given by: f (x) = − ( 1 e2 σ 2π 1 x−µ 2 ) σ • The random variables X and Y are independent if PX,Y (x, y) = pX (x)pY (y) all x, y • Alternatively, X and Y are independent if pX|Y (x | y) = pX (x) and pY |X (y | x) = pY (x), all x,y • Consider two random…
Essential Understanding/Objective/Chapter Alignment Chapter 1: Stats Starts Here (Pages 25) Chapter 2: Data (Pages 611) How do we identify the Who, What, When, Where, Why and How of Data? How do we identify the cases and variables in a data set? How do we classify a variable in a data set? How do we identify the units in which variables have been measured for any quantitative variable? How do we describe a variable in terms of its Who, What, When, Where, Why and How…
Testing Procedure Empirical Results Interpretation Event Study Analysis The time line for a typical event study is shown below in event time: T0 T1 0 T2 T3 The interval T0-T1is the estimation period The interval T1-T2 is the event window Time 0 is the event date in calendar time The interval T2-T3 is the post-event window There is often a gap between the estimation and event periods Models for measuring normal performance In an event study we wish to calculate the…
effectiveness of general controls and manual follow-up procedures. When the auditor tests general controls, he or she will usually learn about the effectiveness of the design and testing of application controls. In addition, the auditor may be able to make inferences about the effectiveness of application controls in identifying exceptions through inquiry of knowledgeable individuals who perform manual follow-up procedures. . b. Identify two strategies that might be used to support a low control risk assessment…
how the research question will be answered. A research design should specify how the selection of participants, method of assignment, and choice of measures and time frame work together to accomplish the study objectives. Interval validity – the approximate truth of inferences regarding cause-effect or casual relationships Casual – pertaining to a cause-effect relationship Casual relationship – a cause effect relationship. For ex. When you evaluate whether your treatment or program causes…
are estimation, and hypothesis testing. With the estimation method, the example is used to estimate a parameter and a confidence interval about the estimate is built (RVLS, 2009). Then to make assumptions inferential statistics is utilized from data to more universal circumstances and descriptive statistics is used to explain what exactly is going on with the data. Psychological Examples The statistical information that psychologists use is received from testing. Descriptive statistics give a…
