SAMPLE Population – the group of ALL people or objects that are under study Sample – a sub-set of the population Parameter – a numerical characteristic of a population 1. Population & Sample Means 2. Expected Values 3. Population & Sample Variances 4. Population & Sample Covariances 5. Population & Sample Correlation Coefficients 6. Estimators Statistic – a numerical characteristic of a sample Statistical inference – drawing conclusion about a population based on information contained
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are well defined but some of the possible factors can cause to the deviations and variances. Those possible factors can be eradicated through extra efforts into the process. However the small chances of variance will remain the same because the real business scenarios may vary sometimes than the forecasted one. This report is an attempt to investigate the operational standards and the possible causes of variance in standards and how does it affect customer satisfaction.
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7) Data from a small bookstore are shown in the accompanying table. The manager wants to predict Sales from Number of Sales People Working. Number of sales people working | Sales (in $1000) | 4 | 12 | 5 | 13 | 8 | 15 | 10 | 16 | 12 | 20 | 12 | 22 | 14 | 22 | 16 | 25 | 18 | 25 | 20 | 28 | x=11.9 | y=19.8 | SD(x)=5.30 | SD(y)=5.53 | a) Find the slope estimate‚ b1. Use technology or the formula below to find the slope. b1=rsysx Enter x‚y Data in TI-84 under STAT > STAT
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1.2 Below we list several variables. Which of these variables are quantitative and which are qualitative? Explain. a. The dollar amount on an accounts receivable invoice. Answer – Quantitative as the value is a number b. The net profit for a company in 2009. Answer – Quantitative as the value is a number. c. The stock exchange on which a company’s stock is traded Answer – Qualitative as it is descriptive or categorical. d. The national debt of the united states in 2009. Answer
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at the end of module 1 3 6 4 7 5 4 6 4 7 1 8 1 More 0 Q1 Descriptive Statistics Excel Worksheet b Q2 d Q3 e Q4 b 5. For the following sample of scores: 2‚ 6‚ 1‚ 4‚ 2‚ 2‚ 4‚ 3‚ 2 Mean variance standard deviation 2.889 2.099 1.537 Find the mean‚ variance and standard deviation 6. A sample of size 7 (n = 7) has a mean of M = 9. One of the sample scores is changed from x = 19 to x = 5. What is the value for the new sample mean? New Sample Mean 7 7. Using Excel
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normal random variable: Theorem 1: Suppose Y = ln X is a normal distribution with mean m and variance v‚ then X has mean exp( m + v /2 ) Proof: The density function of Y= ln X Therefore the density function of X is given by Using the change of variable x = exp(y)‚ dx = exp(y) dy‚ We have = Note that the integral inside is just the density function of a normal random variable with mean (m-v) and variance v. By definition‚ the integral evaluates to be 1. Proof of Black Scholes Formula Theorem
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precipitation will influence beak size. • Variances in beak size will influence beak size. MATERIALS The materials needed for this experiment consist of a computer and access to the Evolution Lab on the University of Phoenix student website. In the Evolution Lab there are two islands‚ Darwin Island and Wallace Island. There are seven variables that can be changed to run many different experiments on both islands. The variables are beak size‚ variance of beak size‚ heritability‚ clutch size‚ island
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John Doe Fin 4980-01 Dr. Alex 2/18/2013 Project 1: “Foundations of Portfolio Theory” by. H.M. Markowitz (1991) Foundations of Portfolio Theory by H.M. Markowitz is based on a two part lesson of microeconomics of capital markets. Part one being that taught by Markowitz‚ which is solely geared toward portfolio theory and how an optimizing investor would behave‚ whereas part two focuses on the Capital Asset Pricing Model (CAPM) which is the work done by Sharpe and Lintner. In this article Markowitz
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course was then recorded in hours. The table below summarizes the data collected. From this data we can note that the two methods have a very comparable completion time as the means of both are just above 75 hours. We can also note that the variance is less for the proposed method. To test the difference between the two population means we conducted the following hypothesis test. Ho:u_1-u_2=0 Ha:u_1-u_2≠0 With this hypothesis test established‚ using the information summarized earlier
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were unequal variances amongst both male and female data sets. Results There is a normal distribution of the data with ranges in size from size 5 to size 14 amongst the participants. With these ranges‚ the mean is 9.142‚ with a standard deviation of 2.583 and a variance of 6.670. Appendix B: Male vs. Female data sets‚ show the mean‚ standard deviation and variance for both of these sets respectively. Female data sets have a mean of 7.111‚ standard deviation of 1.131‚ and a variance of 1.281 whereas
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