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Words 873

Pages 4

The median is known as a measure of location; that is, it tells us where the data are. As stated in , we do not need to know all the exact values to calculate the median; if we made the smallest value even smaller or the largest value even larger, it would not change the value of the median. Thus the median does not use all the information in the data and so it can be shown to be less efficient than the mean or average, which does use all values of the data. To calculate the mean we add up the observed values and divide by the number of them. The total of the values obtained in Table 1.1 was 22.5 , which was divided by their number, 15, to give a mean of 1.5. This familiar process is conveniently expressed by the following symbols:

(pronounced "x bar") signifies the mean; x is each of the values of urinary lead; n is the number of these values; and σ , the Greek capital sigma (our "S") denotes "sum of". A major disadvantage of the mean is that it is sensitive to outlying points. For example, replacing 2.2 by 22 in Table 1.1 increases the mean to 2.82 , whereas the median will be unchanged.

As well as measures of location we need measures of how variable the data are. We met two of these measures, the range and interquartile range, in Chapter 1.

The range is an important measurement, for figures at the top and bottom of it denote the findings furthest removed from the generality. However, they do not give much indication of the spread of observations about the mean. This is where the standard deviation (SD) comes in.

The theoretical basis of the standard deviation is complex and need not trouble the ordinary user. We will discuss sampling and populations in Chapter 3. A practical point to note here is that, when the population from which the data arise have a distribution that is approximately "Normal" (or Gaussian), then the…...

...13. Variance and Standard Deviation (expected). Using the data from problem 13, calculate the variance and standard deviation of the three investments, stock, corporate bond, and government bond. If the estimates for both the probabilities of the economy and the returns in each state of the economy are correct, which investment would you choose considering both risk and return? Why? | |Forecasted Returns for Each Economy |Investment |Boom |Stable Growth |Stagnant |Recession |Stock |25% |12% |4% |-12% |Corporate bond |9% |7% |5% |3% |Government bond |8% |6% |4% |2% ANSWER Variance of Stock = 0.10 x (0.25 – 0.033)2 + 0.15 x (0.12 – 0.033)2 + 0.50 x (0.04 – 0.033)2 + 0.25 x (-0.12 – 0.033)2 = 0.10 x 0.0471 + 0.15 x 0.0076 + 0.50 x 0.0000 + 0.25 x 0.0234 = 0.0047 + 0.0011 + 0.0000 + 0.0059 = 0.0117 or 1.17% Standard Deviation of Stock = (0.0117)1/2 = 0.1083 or 10.83% Variance of Corp. Bond = 0.10 x (0.09 – 0.052)2 + 0.15 x (0.07 – 0.052)2 + 0.50 x (0.05 – 0.052)2 + 0.25 x (0.03...

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...estimate of standard deviation, represented by s’, and compare its efficiency with the efficiency of other quick estimates of standard deviation, σ. Research Questions: This study questions whether the proposed calculation of s’ is an efficient quick method of estimating standard deviation, and how s’ compares to past quick estimates of standard deviation. Hypothesis: s’ can be used as a quick estimate of standard deviation by replacing the weighing of individuals by an estimated ranking of the individuals, with the weighing of groups of individuals. s’ is more efficient than other past quick estimates of standard deviation. Main Findings: Except for sample sizes less than 10, s’ is shown to have an insignificant difference when compared with s. There is only a slight increase in bias as the number of groups increases. The use of s’ as an estimate for standard deviation is efficient and is a preferable method of estimating standard deviation when it is more convenient to rank the individuals than to measure them. However, it is probable that in most cases ranking is more difficult than using the standard method of finding standard deviation. The method of calculating s’ used here is more efficient than past recorded estimates of standard deviation. The disadvantages of this method are error due to subjective ranking and the assumption of normality. Non-normality may affect the efficiency of s’. Mead, R. (1966). A quick method of estimating the standard......

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...Standard Deviation Abstract Paper Miguel Ramos, Waleska Molina, Pollyana Cotto, Jessica Casiano, QRB 501 Quantitative Reasoning for Business University Of Phoenix October 30, 2013 Prof. Angel Melendez-Melendez Standard Deviation Abstract Paper The purpose of this paper is to write a basic abstract for each article selected by the member of the learning team and establish for each article the purpose of the study, the research question(s), the hypothesis of the study, and the main findings of the study. The articles selected by each members of the learning team were: Explaining satisfaction in double deviation scenarios: the effects of anger and distributive justice (Jessica); Consumer Socialization in a Wired World: The Effects of Internet Use and Parental Communication on the Development of Skepticism to Advertising (Waleska); Real Estate in the Real World: Dealing with Non-Normality and Risk in an Asset Allocation Model (Pollyanna); and Social network productivity in the use of SNS. (Miguel). In the student (Jessica) article is an article in where the research has shown that more than half of attempted recovery efforts only reinforce dissatisfaction, producing a double deviation effect. Surprisingly, these double deviation effects have received little attention in service marketing literature. To fill this gap, this article aims to develop and empirically test a model of how customers form satisfaction judgments in double deviation scenarios. The article......

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...Abstract Hearing protectors are used in business to lessen the affects of noise exposure in construction, forestry, or other industrial settings. The purpose of this study was to analyze the relationship between attenuation performance and standard deviation. Businesses expect that hearing protectors provided to employees will reduce the noise level that they are exposed to, resulting in noise at an acceptable level. The hypothesis was that the attenuation performance of the hearing protector would fall within a reasonable range of values, or a norm. Research questions are whether or not various hearing protectors are reliable based on their attenuation performances, how reliability varies adversely with the mean attenuation and standard deviation, and the implications for the utilization of hearing protectors in the workplace. Test data indicated that attenuation performance varies based on the type of hearing protector used and the person using it; however, hearing protection devices should be designed so that the majority of people experience similar levels of attenuation. Results of the study also indicate that a large number of staff who use hearing protectors are actually protected more than necessary. Because of this they may be less likely to use the hearing protectors because they feel that they do not need them, especially in environments where they may experience lower noise levels. Exposure to high levels of workplace noise regularly can cause harm to employees’...

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...in solving this problem is to calculate the mean (x bar), the median (mu), and the standard deviation (s) of the sample. All of those calculations were easily computed in excel. The mean was computed by entering: =average, the median by: =median, and the std. dev. by: = = std dev. The corresponding values are x bar = 14.87, mu = 14.8, and s = 0.550329055. The next step in solving the problem is to construct a 95% confidence interval for the average amount of the company’s 16-ounce bottles. The confidence interval was constructed by drawing a normal distribution with c = 95%, a = 0.050, and Zc = 0.025. The Zc value was entered into the Z◘ (z box) function in the Aleks calculator that resulted in a Z score of +1.96 and -1.96. We calculate the standard error (SE) by dividing the s by the Square root of n which is the sample size. The margin of error is calculated by multiplying the z score = 1.96 by the std. dev. = 0.5503/the square root of n = 5.4772. The result is a 0.020 margin of error. The margin of error is added to and subtracted from the mean to give two numbers the lower and upper values. The lower value is 14.85 and the upper value is 14.89. So, we can say that with 95% confidence the mean of the sample is between 14.85 and 14.89. The next step in solving the equation is to complete a hypothesis test. For this test the null and alternative hypotheses must be identified. Since the claim is that the sample is less than the mean....

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...2.1 Create information for decision making by summarizing data using representative values The questionnaire set out to seek for information from people on their view of Starbucks product. It sought to find out about people’s perception of Starbucks product. That is ‘why they tend to purchase it’. 40 persons were interviewed with a structured question. The information obtained are thus shown below. The representative values used here are the mean, median, mode and standard deviation. Table 1 showing the mean, median, mode, Standard Deviation for each questionnaire response |Table 1. Statistics | | | |Table 2. Responses from Questionnaires | |Personal Details |Frequency |Percentage | |Age |Up to 18 |6 |15.0 | | |18-30 years |14 |35.0 ...

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...body of the paper. When the names of the authors of a source are part of the formal structure of the sentence, the year of the publication appears in parenthesis following the identification of the authors, for example, Smith (2001). When the authors of a source are not part of the formal structure of the sentence, both the authors and years of publication appear in parentheses, separated by semicolons, for example (Smith and Jones, 2001; Anderson, Charles, & Johnson, 2003). When a source that has three, four, or five authors is cited, all authors are included the first time the source is cited. When that source is cited again, the first author’s surname and “et al.” are used. See the example in the following paragraph. Use of this standard APA style “will result in a favorable impression on your instructor” (Smith, 2001). This was affirmed again in 2003 by Professor Anderson (Anderson, Charles & Johnson, 2003). When a source that has two authors is cited, both authors are cited every time. If there are six or more authors to be cited, use the first author’s surname and “et al.” the first and each subsequent time it is cited. When a direct quotation is used, always include the author, year, and page number as part of the citation. A quotation of fewer than 40 words should be enclosed in double quotation marks and should be incorporated into the formal structure of the sentence. A longer quote of 40 or more words should appear (without quotes) in block format with......

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... Nicole Lynn Hicks 716 F Ave. #5 Coronado, CA. 92118 US Evening Phone: 509-449-6253 - Ext: Day Phone: 509-449-6253 - Ext: Email: nlhicks662@msn.com Availability: | Job Type: Permanent, Recent Graduates, Internships Work Schedule: Full-Time, Shift Work | | Desired locations: | United States - WA | | Work Experience: | | | | | FRCSW Naval Air Station North Island Coronado, CA 92118 United States 09/2015 - Present Salary: 56,595.00 USD Per Year Hours per week: 40 | Series: 0850 Pay Plan: GS Grade: 07 | Electrical Engineer (This is a federal job) | Duties, Accomplishments and Related Skills: •Solving difficult electrical engineering problems with design systems to assess feasibility, operating condition effects, and necessity of modification. •Modifying electrical designs and/or drawings packages to meet engineering requirements. •Using engineering computed aided design and/or drafting tools to provide engineering documentation for planning. •Implementing standardized processes and/or principles to develop new electrical designs. | Supervisor: Gary Middlebrook (619-545-5880) Okay to contact this Supervisor: Yes | | | | | Sparton Electronics 2720 Kelly Ave Watertown, SD 57201 United States 09/2014 - 09/2015 Salary: 52,000.00 USD Per Year Hours per week: 50 | | Quality Engineer | Duties, Accomplishments and Related Skills: Na | Supervisor: Marty Geffre (605 -878-1685) Okay to contact......

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...QRB 501 WEEK 4 STANDARD DEVIATION A+ Graded Tutorial Available At: http://hwsoloutions.com/?product=qrb-501-week-4-standard-deviation Visit Our website: http://hwsoloutions.com/ Product Description PRODUCT DESCRIPTION QRB 501 week 4 Standard Deviation, Standard Deviation Introduction Standard deviations (SD) and variance are commonly used statistical tools that measure dispersion, risk, and predict certain outcomes in the business world through data. Through decades of academic research, investors and businesses have settled on standardized norms or patterns for various types of calculations, using standard deviations. Data sets, like mean or median, are manipulated to make an inference. This abstract will highlight five articles where the SD is assimilated in mixt conditions or settings. Each article will classify the purpose, any research questions, hypothesis, and the main findings. What to Use to Express the Variability of Data: Standard Deviation or Standard Error of Mean? Statistics is a major element in any industry, failing to provide adequate information to the reader can easily mislead the receivers. Therefore, using the correct highlights to display the variability of data, can minimize error and clarify any study. According to Barde (2012), “It is depressing to find how much good biological work is in danger of being wasted through incompetent and misleading analysis” (p. 113). Case in point, this experiment was based on the hypothesis that......

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...QRB 501 WEEK 4 STANDARD DEVIATION To purchase this, Click here http://www.activitymode.com/product/qrb-501-week-4-standard-deviation/ Contact us at: SUPPORT@ACTIVITYMODE.COM QRB 501 WEEK 4 STANDARD DEVIATION The Learning Team assignment this week is a simple but helpful assignment. The assignment will consist of a cover sheet, abstract pages, and a reference page. Research, as a Learning Team, 1 peer-reviewed article per team member on the topic, "standard deviation use in the business world" in the University Library. Each Learning Team member must choose a different article. Write a basic abstract for each of your selected articles. Your abstracts must include the following: The purpose of the study The research question(s) The hypothesis of the study The main findings of the study Include APA-formatted references on the reference page. Format your assignment consistent with APA guidelines. Click the Assignment Files tab to submit your assignment. Activity mode aims to provide quality study notes and tutorials to the students of QRB 501 week 4 Standard Deviation in order to ace their studies. QRB 501 WEEK 4 STANDARD DEVIATION To purchase this, Click here http://www.activitymode.com/product/qrb-501-week-4-standard-deviation/ Contact us at: SUPPORT@ACTIVITYMODE.COM QRB 501 WEEK 4 STANDARD DEVIATION The Learning Team assignment this week is a simple but helpful assignment. The assignment will consist of a cover sheet, abstract pages, and a......

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...Standard Deviation (1 of 3) Introduction So far, we have introduced two measures of spread; the range (covered by all the data) and the inter-quartile range (IQR), which looks at the range covered by the middle 50% of the distribution. We also noted that the IQR should be paired as a measure of spread with the median as a measure of center. We now move on to another measure of spread, the standard deviation, which quantifies the spread of a distribution in a completely different way. Idea The idea behind the standard deviation is to quantify the spread of a distribution by measuring how far the observations are from their mean, x. The standard deviation gives the average (or typical distance) between a data point and the mean, x. Notation There are many notations for the standard deviation: SD, s, Sd, StDev. Here, we'll use SD as an abbreviation for standard deviation, and use s as the symbol. Calculation In order to get a better understanding of the standard deviation, it would be useful to see an example of how it is calculated. In practice, we will use a computer to do the calculation. Example: Video Store Customers The following are the number of customers who entered a video store in 8 consecutive hours: 7, 9, 5, 13, 3, 11, 15, 9 To find the standard deviation of the number of hourly customers: 1. Find the mean, x of your data: (7+9+5+. . .+9) = 9 8 2. Find the deviations from the mean: the difference between each......

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...the means and standard deviations for the each group: governors and CEOs. b. Explain, to a person who has never had a course in statistics, what you have done. c. Note the ways in which the means and standard deviations differ, and speculate on the possible meaning of these differences, presuming they are representative of U.S. governors and large corporations’ CEOs in general. 7. Radel and colleagues (2011) conducted a study of how feeling overly controlled makes you desire—even unconsciously—more freedom. In their study, 52 Canadian undergraduates played a video game in a laboratory and were randomly assigned to one1 of the following: • An automony deprivation condition, in which they were told to follow instructions precisely, constantly given instructions over a loudspeaker, and carefully observed on everything they did. • A neutral condition, which was much more laid back. After this activity, they were asked to do a lexical decision task (a standard approach for measuring unconscious responses), in which they were shown a series of words and nonwords in random order and had to press C if it was a real word or N if not. Half of the real words were related to autonomy (such as freedom and choice), and half were neutral (such as whisper and hammer). The key focus of the study was on how long it took people to press the button (response latency) for each kind of real word, averaged over the many words of each type. The table below shows the mean and standard......

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...QRB 501 WEEK 4 STANDARD DEVIATION To purchase this tutorial visit here: http://wiseamerican.us/product/qrb-501-week-4-standard-deviation/ contact us at: SUPPORT@WISEAMERICAN.US QRB 501 WEEK 4 STANDARD DEVIATION The Learning Team assignment this week is a simple but helpful assignment. The assignment will consist of a cover sheet, abstract pages, and a reference page. Research, as a Learning Team, 1 peer-reviewed article per team member on the topic, “standard deviation use in the business world” in the University Library. Each Learning Team member must choose a different article. Write a basic abstract for each of your selected articles. Your abstracts must include the following: • The purpose of the study • The research question(s) • The hypothesis of the study • The main findings of the study Include APA-formatted references on the reference page. Format your assignment consistent with APA guidelines. Click the Assignment Files tab to submit your assignment. QRB 501 WEEK 4 STANDARD DEVIATION The Learning Team assignment this week is a simple but helpful assignment. The assignment will consist of a cover sheet, abstract pages, and a reference page. Research, as a Learning Team, 1 peer-reviewed article per team member on the topic, “standard deviation use in the business world” in the University Library. Each Learning Team member must choose a different article. Write a basic abstract for each of your selected articles. Your abstracts must include the......

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...appropriate statistical tools, interpret the results and provide necessary advice to the investors as research analyst. CASE STUDY 2 (20 Marks) Given below are the returns on the three stocks Supertex, Colourtex and Wivetex for a four year period. Compute the average returns, variance and standard deviation if a portfolio is constructed such that the stock has lowest standard deviation accounts for 50% of the funds, a stock having the next lowest standard deviation accounting for 30% and the third stock accounting for 20% of the funds. In September 2006, Mafatlal Ltd. Paid 10% dividend and in October, 2006 Nataraj Ltd. Paid 30% dividend. On 31-3-2007, market price of shares of Mafatlal Ltd. And Nataraj Ltd. Were Rs.220 and Rs.290 respectively. Pruthvi Hardware ltd. have been informed by their investment advisor that :- 1) Dividend s from Mafatlal L Ltd. And Nataraj Ltd. For the year ending 31-03-2008 are likely to be 20% and 35% respectively. You are required to 1) Calculate the average return from the portfolio for the year ended 31-03-2007. 2) Advice P Ltd. Of the comparative risk of two investments by calculating the standard deviation in each case. CASE STUDY 4 (20 Marks) A) The following table provides details about three mutual fund portfolios. Find out the Sharpe, Treynor and Jensen Index and rank them. What are your suggestions to the investors? 1. The beta of Equity fund is higher than the Beta of......

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...Standard deviation is key to predicting price volatility Wednesday, December 03 - 2008 at 12:10 Prices move up and down; all the time. Sometimes a little, but every now and then by large amounts. The measurement for these movements is called volatility, and is measured using standard deviation. Volatility is the most important price driver of option premiums. We are interested in future volatility. However, this is the only kind of volatility that we cannot know. We are able to calculate historical volatility, but is this a good bias for future volatility? Every option pricing model tries to evaluate options by ascribing probabilities to several different possible prices of the underlying value at expiry. Because the distribution of prices occurs in the future, and every underlying value has its own characteristics, there is no clear answer to the question of how probabilities must be allocated. But, as an approximation, most models (some with adjustments) start with the assumption of a normal distribution. A normal distribution curve is always defined by two things: the average or mean (reflected by the spike in the figure below) and the standard-deviation (the speed of expansion of the curve). The standard deviation can also be interpreted in terms of a probability of an occurrence. Once you know a certain mean and standard deviation, it is always possible to calculate the probability of an occurrence within a certain range of the mean. Usually......

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